Digital PDFs

EK-DMVQM-UG-003

2000

203 pages

Original

8.9MB

view download

OCR Version

8.5MB

view download

Document:	QMA DMV11 Synchronous Controller User's Guide
Order Number:	EK-DMVQM-UG
Revision:	003
Pages:	203
Original Filename:

OCR Text

EK-DMVQaM-UG-003

QMA DMV11
Synchronous Controller
User's Guide

dlilgliltiall|

EK-DMVQM-UG-003

QMA DMV11
Synchronous Controller
User's Guide

Prepared by Educational Services

of
Digital Equipment Corporation

1st Edition, January 1984
2nd Edition, November 1986
3rd Edition, August 1988

The information in this document is subject to change without notice and should

not be construed as a commitment by Digital Equipment Corporation. Digital
Equipment Corporation assumes no responsibility for any errors that may
appear in this document.

Printed in U.S.A.

This document was set on a DIGITAL DECset Integrated Publishing System. Book production was done by Educational Services Development and
Publishing in Merrimack, N.H.

Class A Computing Devices:

Notice: This equipment generates, uses, and may emit radio frequency energy.

The equipment has been type tested and found to comply with the limits for a
Class A computing device pursuant to SubpartJ of Part 15 of FCC Rules, which
are designed to provide reasonable protection against such radio frequency interference
when operated in a commercial environment. Operation of this equipment in a
residential area may cause interference in which case the user at his own
expense may be required to take measures to correct the interference.
The following are trademarks of Digital Equipment Corporation:

luan
Engf
DEC

DECmate
DECset
DECsystem-10
DECSYSTEM-20
DECUS

g?BC(;NIfiterS

MASSBU
PDP
P/OS
Professional
Rainbow
RSTS

gfffélar

ULTRIX
UNIBUS
VAX
VMS
VT
Work Processor

CONTENTS

Page

INTRODUCTION .....cooimiiiiiiieeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeoeoeeeeeeee
e 1-1
INTRODUCTION TO MULTIPOINT ........ouooeeoeoeoeooeoeoeooeoo
oo 1-1
DMV11 GENERAL DESCRIPTION ........ooooooomoooooooeoooo
o 1-1
STANDARD APPLICATIONS ...
1-3
DMV11 SYSTEM OPERATION ........c.cooooimmmeeeeeoeoeoeoe
oeoeee 1-3
COMMAND/RESPONSE STRUCTURES ......oooommoooooo
oeoo 1-5
Input Commands..........ocoueueueuieierieeeeeeeeeee e
1-5
OUtput RESPONSES..........veiereiieeceetceeeeeeeee oo
1-5
PROTOCOL SUPPORT ...t
1-5
Data MESSAZES...........cccote
rmmiii
e
niiieieeeeeeeeeee 1-7
Control MESSAZES..........vuvurevieieieeteeeeeeeeeee et
1-7
Maintenance MESSAZES ............ovueueieieeeeeeeeeeeeeeeeeeeeeeeoeeeeoeoeeoeoeoeoeoooo
1-7
GENERAL SPECIFICATIONS ...t
1-7
Environmental Specifications .................oooeueueeeoeeeoeooooooo
1-7
Electrical Specifications .............o.ovovvecueeeeeeeee oo
1-8
Performance Specifications ................coooeueueueeeeeoeoeoeoeoeoooo
1-8

—
N

N
W

—
N
W

etk

ek e

et ek et

ek o

INTRODUCTION

20000 NNV
LE L=

CHAPTER 1
ek

PREFACE

CHAPTER 2

INSTALLATION

2.1

INTRODUCTION ......coouiiiiiimiiimeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeoeeeeee

2.2
2.3
2.4
2.4.1
24.2

2.5
2.6
2.6.1

2.6.2
2.6.3
2.6.4
2.6.5
2.7

2.7.1
2.7.2

2.8
2.8.1

2.8.2
2.8.3
2.8.4

2.8.5

UNPACKING AND INSPECTION ........oooomomimomooooooeoo

eo 2-1

oo 2-1
INSTALLATION CONSIDERATIONS ..o
2-1
PREINSTALLATION CONSIDERATIONS........oomomooe
ooooo 2-1
Device Placement ..........coooiuiuiuiioiiiieieeeeeeeeeeeeeeeeeoeeeeeee
2-5
System ReqUIrements. .........o..ovvieieeoeeeeieeeeeeeoeeoeeeoeoooooo
2-5
INSTALLATION . ...ttt
2-9
DMVI11 SYSTEM TESTING ......oooimeoeeeeeeeeeeeeeeeeeeeeeeeoooo
o 2-41
Functional Diagnostic TeSting ............ccoveveueeemomemeeooeeooeoooooooI
2-41
DEC/X11 System EXCICISET ............ououeeeeeeeeeeeeeeeeeeeeoeoeoeeoeooeooooooo
2-41
Final Cable Connections.................o.voveueeeeemeoeeeeeeoeoeeoeoooooooooo
2-41
DMVI1T Link TeStNg .....ocovuveieiveeiveeiceeeoeee oo
2-41
MDM Dia@OSHICS .....v.eveeieeeeeeece et
2-41
DMV11-SF SYNCHRONOUS INTERFACE OPTION....oo
oo 2-42
BA200 Series System ENcClosures .............cooovevevevoooooooooooo
ooo 2-43
Module Differences...........oovuiuiuiuiueceieceeeeeeeeeeeeeeeeoeoeeeeeooo
2-44
INSTALLATION. ....c.otitiiiiitee
e 2-44
Unpacking the Option Kit ............cocooueueueemmeoioooe
2-44
Inspecting the FCC and EOS CHPS ......cooooveveveeeeeeeoooeooooo
ooo 2-45
Software BaCKUP.........vrueuevieieeieeieeeeeeceeeeeeeeeeeeoeeeeoeoeoeeeoooooo
2-46
ConfigUration ..........c.ocouueueueiieieeiecceeeeee e
2-46
Checking the System Configuration ...............cocooeoooooio
oooo 2-46

111

CONTENTS (Cont)
Page

2.8.6

2.8.6.1
2.8.6.2
2.8.6.3
2.8.7

a0
DN

[

2.8.7.2
2.8.8
29
2.10
2.11
2.11.1
2.11.2

CHAPTER 3

Guidelines for Module Placement ...........oooceeeimniieiiiiiniiin i 2-49
s 2-49
BUS CONMUILY .. evveevieiieeieeie et sttt
2-49
t
POWET SUPPHES .....evereeeeeieereieieieinte e
2-50
tt
et
eree
DMV 11-SA BUS PriOTItY ..occveeeiieeiee
Finding CSR Addresses and Interrupt VECLOrs........coeoveiiniiininniiieneey 2-50
iiiiir 2-50
tt
iieeere
e eets et
X SYSTEINS. ....veeueeeeer
MICTOVA
niiiiie 2-52
oieininii
...ccccoo
Configuring the DMVI1-SF Option...
o 2-53
..
N
SHUTDOW
OPERATING SYSTEM SOFTWARE
2-53
tt
.t
TESTING THE SYSTEM ..
2-53
tt
.t
..
RELOCATING EXISTING MODULES
2-53
e
e
ettt
ieeeeee
Modules With HanAIEs.........cooooerreeeeiiee
ee e 2-56
sernsessirse
Modules With Blank COVETS .......covveeirivreereeeeeireeenitirisinee
, 2-56
iiiiiiiecce
......ccooi
NS
CONNECTIO
VERIFYING THE GROUND
2-60
e
iiiiiiiiie
......cccccooi
MODULE
INSTALLING THE DMV11
2-60
.
.
.
DEVICES
CONNECTING EXTERNAL
COMMAND AND RESPONSE STRUCTURES

3.3.2
3.33
3.3.4
34
3.4.1
3.4.2
3.4.3
3.5

bt e ssan e sanss 3-1
ere s e bbaasar s s eessrae
INTRODUG GTION ..o eetteeeieeeeeaeasaeeeesiaeeesn
3-1
t
.
.
.
E
COMMAND STRUCTUR
3-1
,
e
iiiiiiiiiii
.......eovveerveer
REZISTETS
Control and Status
3-5
iierise
s
eineinieie
euirieriri
.......cov
OVETVIEW..
Input Commands
iniiii 3-5
e
Output Responses OVEIVIEW .........coeiuiiiiiinininie
3-6
tt
.t
..
COMMANDS
DMV11 INPUT
3-6
o
..
Command
tenance
Control/Main
or
Microprocess
e 3-6
e
eeriirire
e eesrrirre
Mode Definition COommand ............cooeeurmrrrerrr
3-9
aate
reeesans
eeeeerirseaes
aansesesersreeessns
e
s
ererreeeeeeer
eeeeeeeeieeee
....cooeeeeii
COmMMEANA....
Control
3-16
nininnnn,
.cc.cooeiinini
Command.......
(BA/CC)
Count
acter
Address/Char
Buffer
DMV11 OQOUTPUT RESPONSES ...ttt 3-18
Buffer Disposition RESPONSE ........ccooviiuimmiiirieiiiinin 3-19
CoNtrol RESPONSE. ...c..eeueerirteriieiiitiiie ettt 3-20
Information RESPOMSE.......evveeuirtiiriiiieiiiiie et 3-26
TSS/GSS ACCESS......oo ettt 3-26

CHAPTER 4

PROGRAMMING TECHNIQUES

3.1
3.2

3.2.1

3.2.2
3.2.3
3.3
3.3.1

o st o s

es 4-1
sssssas
sseaesisa e s sneesieeessnnnesan
INTRODUGTION ...ttt eeeeeeeteeeeaaeesbteesebreeeee
COMMAND/RESPONSE DISCIPLINE AND HANDSHAKING ........cccc.cccco0. 4-1
Command DISCIPLNE ......ccveevirueeririeiiiiiiie e 4-2
Retrieving RESPONSES.......cerverierueiiiiiiiiiree ettt 4-3
ereiieiee 4-3
et
iteeeiueee
CSR. Interface INtETaCtions .........ccoveee
t 4-3
e st ne st
tt
ettt
DMV 1T START-UP oo
Configuration Procedure ............cocoiiiiiiiieiniinine 4-4
Specifying User-Defined Parameters.........ccooueveerinniinnnnies 4-4
iiiii 4-6
Specifying TSS Parameters.........oovirrierineiniiie
Specifying GSS Parameters.........cooiiiiinieniic 4-11
Protocol OPETAtION ......veeveeieeiieiirieieiiii ittt 4-13

CONTENTS (Cont)
Page

4.4

CRITERIA FOR DETERMINING COMMUNICATIONS LINK

PARAMETERS ......cooooiieeeeeeeeeeeeeoee

4.4.1
4.4.2

4.4.3
4.5
4.5.1

4.5.2
4.6

4.6.1
4.6.1.1
4.6.1.2

4.6.2

4.6.2.1
4.6.2.2
4.6.2.3

4.7

4.7.1
4.7.2

4.7.3
4.7.4

4.74.1
4.7.4.2
4.7.4.3

4.8

B L RO e

98]

— O 00 <N

A L

CHAPTER 5

et 4-13
Setting the Selection Interval Timer.........coooovovooovoooo
oo 4-14
Setting the Babbling Tributary Timer ...........ocovovovooooooooo
o 4-16
Setting the Streaming Tributary Timer.............o.oooovoooooooooo
4-16
ERROR COUNTER ACCESS........oooietoeoeeeeeeeeeeeeeeeeeeoeeoeeo
ooooo 4-17
Reading the Counters..........o.oooiiuoviiieoioe oo
4-17
COUNLET SKEW........cuuveieiieiieeieieeeeeeeeeeeeee oo
4-17
ERROR RECOVERY PROCEDURES. .........cocooo
voiiii 4-17
Recovery from Network Errors ............oooeeeooomoo
ooooooo 4-18
Recovery from Threshold Errors.........c.oooovmomooooo
oooo 4-18
Recovery from Babbling and Streaming Tributary Errors .............o.oo..........
4-18
Recovery from Procedural Errors.............coooovoovooemooo
iooo 4-18
Recovery from a Nonexistent Memory Error ........o.ovovoo
oooooooooooo 4-18
Recovery from a Receive Buffer Too Small Brror........ovoveooeooo
o 4-19
Recovery from a Queue Overflow Error......ooovovvoevooo
oooooo 4-20
BOOTING A REMOTE STATION ........ootormmmoo
eooeeoooooooo 4-20
Steps Leading to a Remote Load Detect BOOt.........oovoo
ooooo 4-21
Steps Leading to a Power-On Boot...........cooooveee
moeooo 4-21
Steps Leading to an Invoke Primary MOP BoOt........oooooo
oooooooo 4-22
DMV11 Switch Settings for the Boot Functions..............o
.ooooooooooooo 4-22
Switch Settings for the Power-On Boot Function.............ooo
ooooooooo 4-22
Switch Settings for the Invoke Primary MOP Boot Function..........
...... 4-22
Switch Settings for the Remote Load Detect Boot Function............
....... 4-23
MAINTENANCE REGISTER EMULATION.........cc
ooooooo 4-23

ASPECTS OF DMV11 MICROCODE OPERATION
INTRODUCTION .........ccooooiimieimimnmiieeeeeeeeeeee
eeeeeeeeoeeoeoeeoooooooo 5-1
DMV11 POLLING ALGORITHM.........c.cooooomomo
momooooooooo 5-1
Calculating Polling Urgency...........o.v.eeceeeeeeeeoseeoso
oooooooooooooo 5-2
Criteria for Determining Polling Parameters..........oo.o
ooovoovoovoo 5-6
Determining a Value for DELTA T.......cooooovo
mommoo 5-6
Determining Values for Q and R ...........coco
oovvoeomoeo 5-7
Determining a Value for Poll Delay ........oococoo
vovevooo 5-8
Determining a Value for DEAD T.........cocooooooo
oooooooo 5-8
ERROR COUNTERS .......c.oomtuiimiimeieeeeeoeeeeeee
eeeeeeoeoooooooo 5-8
Data Link Error Counters ..............o.oo.ovueoeeeomeomeeo
oooooooooooooo 5-9
Data Errors Outbound .............o.ovovovvcoo
ioooeoo 5-9
Data Errors Inbound...........c.ooovivovoooooooe
oooooooo 5-11
Local Reply Timeouts...........oo.ouverveveeeeeeomoeoo
eoeooooooo 5-11
Remote Reply Timeouts. ..............ov.veeoeeeeeeeeoeoooo
ooooooo 5-11
Local Buffer EITors.........ocoouuvvuiviuiooeieeeeoeeee
eeeoeooooooooo 5-12
Remote Buffer Errors........oo.vvoeoveioeoeo
oeooeooooo 5-12
Selection TIMEOULS ..........overveveieceeeeeeeeeeeeooe
oooooo 5-12
Data Messages Transmitted...............cocoooovov
eoeoeooo 5-12
Data Messages Received ..............o.ooooueoemomoeo
sooooo 5-12
Selection INtervals...........oouvveveeieieioeieeeee
eeeeeooooooo 5-13

CONTENTS (Cont)
Page

APPENDIX A

DDCMP

W N —

W
-

VRV RV RNV RV NV RV RV
o o L
) W W W WL W

5.4.2
54.3
543.1
5.4.3.2

StAtION ErTOT COUINLETS ...euueeeeeeeeeeeeeeieeeeeeeeraaaeaeeaaaeeseaeseareeernirnnraserteetensatasearaaaaaaes 5-13
Remote Station FITOTS .ooovieeeeeeeeeecreeeeeeevrreeeeeereeeeeserrereeeesseaasssssbsanessnstaaneaenes 5-13
terere 5-13
LOCAL StALION FTTOTS. .. eeeeeeeeeeeeeeeeeeeeieeeereareneeaaeseeeeeeesieeeaerassnrrare
5-14
e
iiiiriiene
eeeiiieiieiii
....uueviiier
EITOrS
ck
Global Header Block-Che
5-14
o,
..
Errors
ck
Block-Che
Maintenance Data Field
5-14
eessemiamminn
sassasassssassse
eernsnesssesssss
eeeseeeeeeeeerse
.vuueereeeeeeres
.
ThreShold ErrOr COUNTETS
5-14
e
s
erereereee
aes
e
e
e
e
e
ieenmeeeie
iiieieeiii
c.cooiieie
EITOrS....
Transmit ThreShold
5-15
eerre
e
ieiiee
e
iiiiii
oeeeee
..oooo
EITOrs
Receive Threshold
5-15
eeeee
eeeseseeeees
rreeeeee
e
reeeeere
iiiieeee
.oeeeeee
EITOTS
Selection ThreShOld
5-15
cecee.
........c.
OVERVIEW..
BASE
DATA
L
INTERNA
DMV11 MICROCODE
5-15
e
s
e
abass
ssraasarnbasss
eeasesnsaennns
nannsssseeeeee
eeesesesusssss
eeeeeeeeeeeeee
LLANKEA LLISES woneenneeeeeee
5-16
s
rssnnsaannaeaens
teereeeeernrrars
eaeeeseseeeerete
eeeiiiieieiiiree
...oooveeeeeeeie
LISt
The Free LiNKEd
5-18
i
inieeii
iiiiiii
ooooiei
.......
LSt
Linked
The Response
5-18
ess
ssrreaeeeeaeeees
eesessnnnrbrssss
reeeereeeeeeeeee
eeeceeieeemeeree
.ooeeeeeeieeeeee
LiStS
BUffer LiNKed
5-19
e
iiiiiiee
.ccoeriimiii
Table.......
Slot Mapping
TSS ANA GSS SEIUCTUTES ..vvvveeereenirieeeeeeeeeirreteeteeeessaassrsesensasssssassesassnrnieesssssanns 5-19
The Global Status SIot (GSS) ....oooveeiieeieere e 5-19
Tributary Status SIots (TSS) .....ccovirmiiiireinei 5-19

5.4.1

R
R

U9 DD bt

et ket

54.1.1
54.1.2
54.1.3

APPENDIX B
B.1

B.2
B.3

OP PP PRI A-1
| X300TS TR SOOI
0]D63\,
Controlling Data Transfers. ..o A-1
Error Checking and ReECOVETY.......cccoiiiiiiiiiiiieinc A-1
Character COQINE......c.oeoveruerierrereeieeeiee et A-2
ste A-2
st
erassee
e st
s et etearensr
Data TTANSPATEIICY ..veveveemeeiereinris
eseees A-2
asasssssseessnsan
eeeereeee
e s esearartnrrraaaaa
Data Channel UIZAION ....oeeeeeeeeeeeeieeeeeeree
PROTOCOL DESCRIPTION ...oooiiiiiiiee et eeeiirereeeeeeeeeeiiesssesnnnsaessesssssssneseesssnas A-2
e A-4
e s saraasins s sans
aseetreeee
essese
st esasunneseesssss
MESSAGE FORMAT ..ot eeeveeeeeesa
FLOATING DEVICE CSR AND INTERRUPT VECTOR ADDRESSES

FLOATING DEVICE CSR ADDRESSES. ... B-1
FLOATING INTERRUPT VECTOR ADDRESSES......ccccoiie B-4
EXAMPLES OF DEVICE CSR AND INTERRUPT VECTOR ADDRESS
ettt e e e et earreeaesasaasstrtaeeeesessiresesaenrnaaanessessassnntatesseaes B-6
T
ASSIGINIMEN

APPENDIX C

MODEM CONTROL REGISTER FORMATS

C.1
C.2

MODEM CONTROL REGISTER FORMATS ...t C-1
RS-449 VERSUS RS-232-C . .eeeeeeeeeeiieeeeeeeeesennereeeeeeseesnassesensnsasssasessssssnneenessssnes C-4

CONTENTS (Cont)

MODEM CONTROL
MODEM CONTROL........cootiieieteeeeeeeeeee
e
eeeeeeeeee
e e D-1

APPENDIX D
OOU

Page

Hardware Modem COontrol ...........c.oooeioeonioeiieieeeeeeeeeeeeeee e, D-1
Modem Control Implemented by the DMV11 Microcode ..........cooevveeeevevenenn D-1

APPENDIX E

QMA DMV11 OPTION CONFIGURATIONS

E.l

INTRODUCTION ..ot
ee
e, E-1
OPTION DESIGNATION CONVERSION ......o.oooioteteeeeeeeeeeeeeeeeeeeeeeeeee
. E-1

E.2
E.2.1

E.2.2
E.2.2.1
E.2.2.2

E.3

E.3.1
E.3.2
E.4

Installed OPtON........coiir
e
irieiieie
ee
eeeee E-1
Add-On OPLION ...ttt
e e, E-1
Base OPLIONS ......uiiiiiieeeeeee
CabINEt KItS...ceiotieeieieieieie

et E-1

e, E-1
OPTION CONFIGURATION SUMMARY ..o, E-1
Base Option DeSiZNations.........c.eeveveoueeieeeieeieeiiieeeeeeeeeeeeeeeeeeeeee
e
e E-3
Cabinet Kit DESIZNAtIONS ........ccveeviene
e eeee e iieieeeee
e e
eee E-3
DMV11 OPTION CONFIGURATIONS ... .o, E-5

FIGURES
Figure No.

=t (WD DD

2-4
2-5

2-6
2-7

2-8

2-9
2-10

2-11
2-12

2-13
2-14

2-15
2-16

2-17
2-18
2-19

2-20

Title

Page

DMV11s Used in Point-to-Point ApplCations ...........eceeeeeeeeeeeeeeeeeeeeeeeeeoeoeoos 1-3
DMV11s Used in Multipoint ApplCations ...........ceeveeoeeeeeereeeereeeeeeeeeoeeeoeeo, 1-4

General Summary of DMV11 Command/Response Structure ...............oovvvoveevenoi. 1-6
Local NetWork TOPOIOZY .....oveuveuiueeuiitieienieeeeeeeeeeeeeee e 2-2

Remote NetWork TOPOIOZY ......ocveveoeieeeieeeeeee e 2-3
MBOS53 SWItCh LOCALIONS ....eveeeeeeti e 2-7
MBO064 SWitCh LOCALIONS ......eouvviiieriteeceieeeeeeeee

e, 2-8
DMV11 Installation FIOW..........c.ooiiomiiiiieieeee e 2-12
DMV11 Switch Selectable FEatures .............ccoooeeoeeeeoeeeeeeeeeeeeeeeeeeeeeoeeeeo, 2-15
Test Connector Insertion for the M8053..........c.omioiiieeeeeeeeeeeeeeeeeeeeeeeeeeeees 2-19
Test Connector Insertion for the M8064............ooveoeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee 2-20
DMV11 Test CONNECLOTS. .....veviueeeieree
e
eeeetieeeeeeeee 2-21
DMV Cable Drawings.........oceieieieuioiieieeeeeeeeeeee e, 2-25
DMVI11 Non-FCC Compliant Cable Drawings .............cocoeeeeeeeereemeeeoeeeoeeoeooeee. 2-28
DMV11 Remote System Cabling DIiagram ............ocoeeeeeeeeeeeeeeeoeeoeoeeeoeooo 2-30

DMVI11 to DMVI1 Integral (Local) Modem Cabling Diagram (Point-to-Point)..... 2-32
Half-Duplex Multipoint Network (Control Station End Node)............cocooveveveevnn... 2-34
Full-Duplex Multipoint Network (Control Station End Node)...........coovevvomeeeenn. 2-35

Full-Duplex Multipoint Network (Control Station Inner Node)............ocoovvvvevvneoi.. 2-36
DMV11 Cabinet Installation to FCC Bulkhead ...........coooeveeveeoeooeeooeo 2-37

DMV11 to RS-232-C Interface Panel (70-20863)............... eeeeereeee
———————————s
eeeee 2-38
DMV11-SA Module (M8053-PA) with Bulkhead Handle.............vvoveomooeoo
. 2-42
BA220 Series Enclosure Chassis............o.ocueeweeeeeeeeeeees oo 2-43

vii

FIGURES (Cont)

B-

— N

— O

U\mwm(lfimu\w
> >
:
o100 ~J O\ L
——\D

MMM#?LL&ML&J UJUJUJLIJJUJUJQ)
O oo U
b by~
GOt — GO =

Page

DMV 11-SF Option Kit CONteNtS......c.cocuieiiiiimiiniiniieniieieniesisteie s 2-45
t 2-46
nicssic
stt
e srsteieereece
FCC and EOS ClIPS ...coovieieieerieeee
iies 2-47
iiimiiiniiiniini
BA200 Series Configuration WOorksheet...........cccoooviiim
2-49
ii
iiiiiiii
Bus Grant Continuity Path ........cccooeii
2-52
M8053-PA Module Layout .......ccceeuereuieeeiieiiiiiiiie et
e 2-54
Releasing the Captive SCIEWS .......cccocviiiiiiiiiiiieieiiieee
e 2-55
Unlocking the Release Levers .......ocociiiiiiiiiiiiniiiiie
2-57
e
Removing the Blank COVET ........ccooiiiiiiiiiniiieicii
2-58
sssssnesessssesens
essntessssnseaeessssasesa
GroUNd CONNECLIONS ....vveeiiieirvereeiereeeeeeisreeeasssreeesaarreee
2-59
iiiiiii
.cccoovoi
Attaching the Gap Filler Assembly .........
2-61
iiiiec
nieemiii
Inserting the MOUIE ........cooveiie
2-62
e
Cable Option AttaChMENt .......ccccveriiiiiiiiiiii
2-63
s
nnesessessasasssnseeessan
eaeineeeeeniireeessieesss
DMV 11-SF Cable CONNECLIONS .....eeeeeeerrrrereeineie
3-2
incniiiinninnnnnn
.........coooieimini
Addresses
DMV11 CSRs Byte and Word Symbolic
3-2
niiiinicnns
...........ccocceiiiin
Responses
and
Fixed and Variable Formats for Commands
3-6
n.
.c.cocooiiiiiiin
Format..........
Command
Microprocessor Control/Maintenance
3-7
ot
11 ..
Initialization of the DMV
Mode Definition Command FOrmat ...........oooeeiiiiiiioeieiiiniiiii e 3-8
e 3-9
Control Command FOTMAt .........oooiuiiiiiriiiereeeeeeeette
. 3-17
..
Format
Command
Buffer Address/Character Count
es 3-19
iiiininincncii
..cocoieieiiii
FOrmat........
Buffer Disposition Response
3-26
e
iieniiiiei
..........ccocovviierr
Control-Out Command FOrmat
3-27
s
iniiiiiiii
........c.cccocviiiiiiii
FOrmat
Information Response
a e 4-2
s eeeeeeee
ereieeeiiie
et
CSR Interface Control BItS......ccoiviitieii
e s ssee e e sanee 4-4
iestee
e
s
e
e
e
ab
e
e
e
sba
s
e
eeireeeess
snte
s
re
et
iiieeeriee
....ooiiee
CSR. ACCESS WINAOW
ns 4-24
cooooeiiiiini
............c
Format
Command
Loop
DMV 11 Maintenance
.. 5-3
T.............c.........
DELTA
and
R,
Q,
Parameters
Polling
Between
Interrelationship
5-4
Interval......
Polling
Minimum
the
and
R,
Q,
Parameters
Polling
Relationship Between
Relationship Between the Default Values for Q and R for the Three

Polling AcCtivity Levels .......ccoeveviiiiiiiiiiieiiei e 5-5
State Diagram of Polling State Transitions..........cccoccevieiienieininninicne 5-7
Data Link and Threshold Error Counters..........cccccomeeeviiiiriiiniimeeeseeeeiienenes 5-10
Station Error COUNETS .....cvvvvveieieeeeeeeiiieeeeeeerreeeeseseeeesesrteessinesssraneseesraseasesnaaessnnns 5-11
s 5-16
Data MemOry MAD ....ocueeiieiiiniiiienictinte e
e 5-17
DMV 11 Linked List Structure FOrmat.........ccooovceeiiiiiiiiiiiiiniin
e e 5-18
sren e en iteeee
eeeiteeeeee
e st
Standard LinK BlOCK .....ccoiivuriiiiieiee
arseesssnsenesaas 5-21
e st e e ssas e s s s nrane s e eiee
e eeireeeeeeebrr e e seereeeieieee
GlODAL SEALUS SOt oeneeeeeieiie
Tributary Status SIOt........cceceeerierereeie it 5-23
eeceitec A-1
e
DDCMP Data Message FOrmat...........ccocveeiiiiiiiiiiiininiceien
DDCMP Message Format in Detail........cc.cooooiiiniiiiniii A-3
UNIBUS and LSI-11 Address Map.....ccccoeveereiiriiiiniiniiiciiceneeene e B-2
Flow Diagram SymDBOIOZY .......c.cererermiriiimiiiiineeii it D-4
rerie D-5
tt
erieeier
ettt et
Modem Control (SEAT).....c.eie
e D-6
Modem Control (TTANSIMIL) .....cceevveerieieieeie
Modem Control (TTanSIMUt 2).....cccveeeeeerireriiieerieeeiie ettt D-7
e D-8
e ease e e
eieenieener
st siae s seesereessa
Modem Control (RECEIVE)........cvveeueeeieeeiee
Modem Control (Modem Status).........cceeeeerierrieriieiiiiiiiiiieeie it D-9
e D-10
Modem Control (Call TIMEr) .....oiiiiiiieiieeie
Modem Control (SHUtAOWN) ...cveeeiviiiiieriie et D-11

Vill

FIGURES (Cont)

E-1

Base Option DESIZNAtion ...........coeeiuiieuiiiuiiieieeeieceieceeeee
et
e e e e e eeeeeaeas

E-2

Cabinet Kit DeSigNation..........c.ceeeiieuieieeeneirieeeeeeeeeeeeee
ettt e e e e eaesene e

TABLES
Table No.

Title

Page

1-1

DMV IT OPLIONS. ....ceiniiiiiieeieiieee ettt
et e e e et es s eeeeeeseee e ae e eseaeeeeeseans

2-1

Typical Host Options of a Bell 208 ATM Data Set (4800 b/s) Full-Duplex

2-2

Typical Tributary Options of a Bell 208ATM Data Set (4800 b/s) Full-Duplex

2-3

OPETALION. ... .ottt
ettt
ettt et et et e estee e e eeeneeaeeneeeeeeseeeneseees
DMV VOIagE Chalt.....cccueeiiiiieeieciieeeeeeeeeeee
et
e e e e eene s

OPETALION. ...ttt
ettt ettt ettt et ee s e e e sae et eeeeseeeeeeeeaenaen.

2-4

Device Address SEleCtion ......ouinuiouieieieiieie et 2-10

2-5

Vector AdAress SEIECTION.......c..covieuiie
e
iieieeieeee
e 2-11

2-6
2-7

DMVI11 E101 (M8053)/E107 (M8064) Switch Selectable Features...................... 2-16

CADINEE KIS .. .eitiiieitieteee ee
t
ttt e e et e e e e e eae s 2-18

2-8

Switch Function Settings on 70-20863 Panel for RS-232-C Interface..................... 2-39

2-9

BC55H Jumper Modem FUnCHONS. .........c.ooviiuiiiiiiiceice

2-10

e 2-40
Power and Bus Load Data ........ccccooeiioiiiiiiiiccceee
e 2-48

2-11

Recommended Module Order............oouieiiiniiieiiieeeeeeee,
eeeeeeeeee 2-50

2-12

Devices Supported by SYSGEN ......ooomiiiieeee

e 2-51

2-13

EXtension CabIes .........cooouiiiiiiiiiieec

3-1

SELO Bit FUNCHONS.......cotiitiiietiitee ettt
et ee e e e e e eneeans

3-2
3-3

e 2-62

BSEL2 Bit FUNCHONS ....ovveuiiiiiiieeeeeeeeeeee ettt

Input Command COdes.........eveveueerieiieieiieeeeceeee

ean e

3-4

Mode Field Codes and FUNCLIONS .........c.ooueiviieiieeiiieiieeceeeeeeeeeee e,

3-5

SEL6 Control Command FUnCtions ..............c.ocuovuieiiiiieeieeeeeeeee e 3-10

3-6

Request Key Field Definitions (Control Command) ..........cccevveeveeeeveeeeeeeeeeeennn, 3-14

3-7

Output Codes (BSELG).......cooiiiieiereeteeeeeeeee
e
e e e eeenas 3-21

3-8
4-2

Return Keys for Information ReSponse..............ocooooviiiuiioeieieeeeeeeeeeeeeeeeeeeeeean, 3-27
D1agnostic EITOr COdes .....ouveuieiiiiieieeiieiieeieeeceeeeeeee
et
se
User-Defined TSS Parameters.........cccuvoviioiieeiiiiieeieieeeeeeeeeeee e,

4-3

User-Defined GSS Parameters ..........co.eeoieiiiuiiiiieiceeeeceeeee
e
eeee 4-12

4-1

4-4

4-5
4-6

B-1
B-2
D-1
E-1
E-2
E-3
E-4

Recommended Selection Interval Timer Values.........co.oooveeeeeeeeoeeeeeeeeeeeeeeeeeeennn 4-15

Mode SWItCh SELUNES ....cuviieeieieieeeeei
et
eeeeeee
e s e e e e eeeesanas 4-23
Maintenance Command Functions BSEL2 Bits 0-3.......c..ccooociiievoneeeeeeeeeeeeeeeeeennn. 4-25

Floating Device CSR Address ASSIZNMENTS ...........ccvevuieueeeeeieeieeeeeeeeeeeeeeeeeeeeeeeennn

Floating Interrupt Vector Address ASSIZNMENTES ..........c.eovveeueeeeeeeereeeeeeeeeeeeeeeeeeeeenns

DMV11 Modem Control FUnCHONS...........c..oovviiiiiiiieeeeeeeeeeeeeeeeeeeeeeee
e, D-2
Option Compatibility Cross-Reference ............c.ocooveiiviieeeeieeeeeeeeeeeeeeeeeeeee
e E-2
Electrical and Mechanical Interface TYPE .......ccoviiiiiiioeeieeeeeeeeeeeeeeeeeeeeeeeee
e
Cabinet Kit COMPONENLS ........cuviuiiuieuieereieeeeeteeeeeeeeeeee ettt

e e e e e e eeaees E-4
DMV 11 Option Configurations........c...cceeereeeu
oot
iiiueeiiiieieeee
ee e eeee
e E-5

PREFACE

The Qualified Modular Assembly (QMA) DMV 11 Synchronous Controller has been tested and meets all
requirements for limiting electromagnetic interference.

This manual has been written to meet the needs of Field Service personnel and contains the following
categories of information:

General description including features, specifications, and functional descriptions,
Installation,

Command and response structures,
Programming, and
Microcode operation.

This manual also includes appendices that discuss DDCMP, floating device and vector addresses, modem
control register formats, modem control, and the QMA DMV11 options and cabinet kits.

NOTE
In this manual, the QMA DMV11 Synchronous
Controller is referred to as the DMV11 for brevity.

CHAPTER 1
INTRODUCTION

1.1

INTRODUCTION

The multipoint DDCMP-DMV11 Intelligent Communications Synchronous Line Controller is a device

which provides efficient high-speed synchronous communications for distributed networks. The DMV11

uses LSI-11 CPUs as control or tributary stations, while requiring a minimum of main CPU resources.
This manual provides detailed information necessary for installing and operating the DMV11.
1.2

INTRODUCTION TO MULTIPOINT

Point-to-point configurations are practical when the message rate of the terminals is high. In many cases,

however, the message rate of the terminals is very low even though the bit rate may be quite high. In these

cases, sharing a transmission line can significantly reduce the cost and improve the efficiency of a
communications network.

Various techniques are used to share transmission lines to improve their utilization. One of these techniques is the use of multipoint lines. In multipoint operation, a single line can be shared among many
nodes. Each node is a station and has a unique address. One station in the network is always designated as

the control station while the remaining stations are designated as tributary stations. Because all stations are
connected to the same line, no two tributary stations may transmit at the same time, and each station must
have a means of recognizing which messages it is meant to receive. The address field of the message
header identifies the station to receive the message. The control station governs sharing of the line by
means of polling in order to authorize transmission to the control station. In a polling operation the
tributaries are in effect asked one by one whether they have anything to transmit. To accomplish this, the

control station sends a polling message with a unique tributary address down the line. The station which
recognizes the address responds by sending data or by sending a positive response.
Tributary stations can only transmit to the control station and only in response to a polling message from

the control station. Transmission between tributaries is not allowed as all message traffic must be routed

through the control station. Control stations on the other hand may transmit to any tributary at any time if

the communicating stations are in full-duplex. In fact, multiple messages for different destinations
(tributaries) can be sent serially by the control station. Each tributary station then, in turn, examines the
address and accepts only those messages it is meant to receive.
The use of communication lines can be maximized by using full-duplex capabilities at the control station to
accommodate many tributary stations on a full-duplex line. In this mode, the control station keeps the lines

full by sending to one or more tributary stations, while at the same time receiving from another tributary

station.

1.3

DMV11 GENERAL DESCRIPTION

The DMV11

is a high-performance line controller which operates at speeds up to 56K b/s. It accomplishes
this by doing DMA transfers.

The available options are listed in Table 1-1.

I1-1

Table 1-1
Base Option and

Cabinet Kit*

DMV11 Options

Interface

Line Speed

EIA RS-232-C

Up to 19.2K b/s

CCITT V.35

Up to 56K b/s

Integral modem

56K b/s only

EIA RS-423-A/449

Up to 56K b/s

DMV11-M

+CK-DMV11-Ax
DMVI11-M

+CK-DMV11-Bx
DMVI11-N

+CK-DMV11-Cx
DMVI11-M

+CK-DMV11-Fx
NOTE:

Refer to Appendix E, Table E-1, for old/new option designation cross-reference
(that is, non-FCC compliant/FCC compliant).
*x = A, B, C, or F as applicable.

Features of the DMV11 include:

Support of point-to-point and multipoint operation,

Support for remote or local, full-duplex, or half-duplex configurations,
Support for 12 tributaries and one control station in multipoint operation,

Switch and program selectable operating mode and tributary address,
Support for multiple addressed tributaries,

Down-line loading and remote load detect capabilities,

Go/No-Go diagnostic testing by the microcode,
Go/No-Go extensive error reporting,
Modem control.

1-2

1.4 STANDARD APPLICATIONS
The DMVI11 can be used with the integral modem as well as with EIA and CCITT applications.
These
applications can be configured as either point-to-point or multipoint networks. Figure 1-1 shows
a typical
point-to-point application and Figure 1-2 shows a typical multipoint application. For local
operations
through integral modems, stations are interconnected by twinax or triaxial cables. The integral modem
can

support up to 12 drops in both half- and full-duplex modes. For remote operations, stations
are connected

through external modems that use common carrier facilities. For specific information on installation
of
either of the basic DMV11 units and associated options, refer to Chapter 2.

LSI-11 CPU

OPERATING

LSI-11 CPU

LOCAL

VUrrCnAILING

SYSTEM

SPERATING

NODE

SYSTEM

USER PROGRAM

DEVICE DRIVER

USER PROGRAM

LSI-11 BUS

[

—i

UsED

3
v

r—--"
NOT

LSI-11 BUS
h

TRIB.

.'
'{

DEVICE DRIVER

£
4

REMOTE

NODE

r—-- "}

fe—; MODEM l<——”——>: MODEM >

DMV11

—

#12

DMV11

MK-2485

Figure 1-1

DMV1l1s Used in Point-to-Point Applications

For multipoint applications, the tributary address for each DMV11 in the network is either switch or
program assigned. In the case of switch-assigned tributary addresses, specific switches on each DMV11

define the numerical value of the address to which that DMV11 responds. The advantage of
a switchassigned tributary address is that it provides data transfer security since the address cannot be changed by
software.
A major advantage of DMV11 multipoint networks is the ability of the main CPU at the control
station to
down-line load programs to the CPU at each tributary and start those programs without manual
intervention. As a result, DMV11-based multipoint networks are particularly suited for installation at remote and
generally inaccessible locations. For example, DMV 11s may be used in remote systems, in hard to reach
locations such as weather stations at sea, and in hazardous environments.

1.5
DMV11 SYSTEM OPERATION
Operation of the DMV11 communications line controller is initiated and directed by a user
program
residing in the main memory. The user program consists of an application program and a device driver
that serves as an interface between the DMV11 and the CPU.

Communication between the user program and the DMV11 is accomplished over the LSI-11 bus through
four control and status registers (CSRs). These four 16-bit registers serve as a bidirectional port
to pass
user-program commands to the DMV11, and DMV11 responses to those commands back to the
user
program. Each of these registers are word and byte addressable by both the user program and the DMV
1
microcode.

1-3

LSi-11 CPU

OPERATING

SYSTEM

USER PROGRAM/]
DEVICE DRIVER

LSI-11 BUS
[4

DMV11

CONTROL
STATION

(INTERNAL

DATA

/ STATUS SLOTS
l="3

<—> MODEM =

- —J

.
#12

v-1

STRUCTURE)

TRIBUTARY

‘_%‘

== 7
| MODEM !

TRIB/STATUS

DMV11

L —f— -

DMV11

MULTIPOINT[

NODE B

MULTIADDRESS

/ STATION

MULTIPOINT [STATUS SLOT
FOR SWITCH
NODE A

OPERATING

SLOTS FOR

SET TRIB.

ADDRESS

MULTIPOINT

OPERATING

SYSTEM

NODE C

OPERATING

SYSTEM

SYSTEM
USER PROGRAM/

USER PROGRAM/
DEVICE DRIVER

|
| MODEM

LSI-11 BUS

DEVICE DRIVER

IVE

g
LSI-11 BUS

USER PROGRAM/
DEVICE DRIVER

LSI-11 BUS

MK-2520

Figure 1-2

DMV1ls Used in Multipoint Applications

NOTE
Normally only four CSRs are available to the user
program. However, in 22-bit address mode, eight
CSRs are available although only one additional 16-

bit register is used.

In this group of four CSRs, the first two have a fixed format and in general serve as a handshake control
for user-program commands and DMV11 responses. The next two CSRs form a port for the exchange of

commands and responses between the user program and the DMV11. Other control fields provide for
initialization, interrupt enabling, reading and execution of maintenance instructions, data transfer setup,
and tributary addressing.
A user program issues a command to the DMV11 by first requesting the use of the data port. When the

DMV11 grants permission to use the data port, the user program passes the command to the DMV11 in

the CSRs. The DMV11 interprets the command and performs the specified actions. If a response is
required, the DMV 11 stores the appropriate response in the CSRs and then informs the user program that

a response is present.

Message data received or to be transmitted by the DMV
11 is written into or read from preassigned buffers
in main CPU memory. These buffers are accessed by the DMV11 through nonprocessor requests (NPRs)

to the associated bus address.

1.6 COMMAND/RESPONSE STRUCTURES
Since the DMV11 is basically an input/output device, it follows that the command/ response set for this
device be categorized as input commands and output responses. Input commands are commands issued by

the user program to the DMV11. Output responses are typically responses to those commands, and are
issued by the DMV11 to the user program.

Some responses are unsolicited, and are used to inform the user program of protocol events and line errors.
1.6.1

Input Commands

Lo
-

There are four types of input commands. They are listed below in the usual order of issuance.
Microprocessor control/maintenance,
Mode definition,

Control,
Buffer address/character count.

1.6.2 Output Responses
Output responses serve to inform the user program of normal or abnormal conditions concerning the data
transfer operation. There are three types of output responses:
l.

Control response,

Information response,

Buffer disposition response.

Figure 1-3 is a general summary of the functions performed by the DMV 11 command/ response structure.
These commands and responses are discussed in detail in Chapter 3.

1.7
PROTOCOL SUPPORT
In DMVI1 point-to-point and multipoint networks, all message transfers between nodes are under control
of the Digital Data Communications Message Protocol (DDCMP). All aspects of DDCMP processing are

handled by the DMV 11 microcode. Message handling at the user-program level only involves setting up
data buffers during transmit operations and accepting data from the DMV11 during receive operations.

1-5

LSI-11

USER PROGRAM

USER PROGRAM ISSUES
MICROPROCESSOR CONTROL
COMMAND TO MASTER

INITIALIZE

DMV11

CLEAR DMVT1

FAILURE

NOTIFY

USER

PROG. VERIFIES

USER

INTERNAL

PROGRAM

DIAG.

SUCCESSFUL,

DMVI11 RUNNING
SET MODE OF HALF-

OR FULL-DUPLEX,

ESTABLISH STATION
AS POINT-TO-POINT
NODE OR MULTIPOINT
CONTROL OR TRIBUTARY

USER PROGRAM ISSUES
MODE DEFINITION
COMMAND

STATION

ESTABLISH TRIBUTARI ES,
SET USER DEFINED

USER PROGRAM ISSUES

PARAMETERS, INITIATE

CONTROL COMMANDS

PROTOCOL STARTUP

ASSIGN TRANSMIT
AND

RECEIVE BUFFERS

USER PROGRAM ISSUES
BUFFER ADDRESS /
CHARACTER COUNT

COMMANDS
RECEIVE

TRANSMIT

{

y
THE DMV11 PERFORMS THE FOLLOWING

THE DMV11 PERFORMS THE FOLLOWING

RECEIVE MESSAGE FUNCTIONS:
1. PROCESS RECEIVE HEADERS

TRANSMIT MESSAGE FUNCTIONS:
1. CREATE DDCMP MESSAGE

2. CHECK CRC's

HEADERS

3. ACKNOWLEDGE (ACK) PROPERLY

2. GENERATE MESSAGE AND
HEADER CRCs

RECEIVED MESSAGES

4. NEGATIVE ACKNOWLEDGE (NAK)

3. TRANSMIT MESSAGES

ERRONEOUSLY RECEIVED MESSAGES

!
1)

THE DMV11 PERFORMS THE FOLLOWING
MESSAGE TRAFFIC CONTROL FUNCTIONS:
1. MESSAGE SEQUENCING

2. ERROR RECORDING AND REPORTING
3. PROTOCOL SUPPORT
4. LINK MANAGEMENT

DMV11 ISSUES BUFFER
DISPOSITION RESPONSES,
CONTROL RESPONSES AND

INFORMATION RESPONSES

MK-2651

Figure 1-3

General Summary of DMV11 Command/Response Structure
1-6

There are no file structure constraints on messages transmitted or received over DMV11 networks:
however, the maximum data message length allowed is 16,383 bytes. Also, there are no restrictions as to

the type of data transmitted or received under DDCMP since all data is transmitted and received in
transparent form.

There are basically three types of DDCMP messages: the data message, the control message, and the
maintenance message (refer also to Appendix A for additional information on DDCMP).

1.7.1
Data Messages
DDCMP data messages consist of two parts: the message header and the message body. The header
consists of eight bytes of control information necessary for successful transmission of the message.

Included in these eight bytes is the block-check count (BCC) for the header, the byte count of the message
body, and the tributary address. The header also contains two control bits; one that indicates resynchronization after this message, and one that controls line turnaround. The message body consists of the
message and a BCC for the message. Both BCC characters are used by the
as they are received.

DMV 11 to validate messages

The header is assembled by the DMV11

and transmitted with the message body to form the data message.
The receiving DMV11 uses the header to verify the address and ensure that the message is received in the

correct sequence. The header is also used to determine the number of bytes to transfer to the user
program. The header is discarded when the message is successfully passed to the user program.

1.7.2
Control Messages
Control messages are used to manage message traffic. They are eight-byte DDCMP messages which are

passed between control and tributary stations under sole control of the DMV11. Two examples of control

messages are acknowledge (ACK) and negative acknowledge (NAK). ACKs indicate successful reception
of messages while NAKSs indicate unsuccessful reception. Control messages in multipoint also contain the

address field to identify the tributary to which the message is sent or received from.

1.7.3 Maintenance Messages
Under DDCMP, a DMVII has two data transfer modes: the DDCMP run state, and the DDCMP
maintenance state. In the run state, a DMV11 receives and transmits data messages. In the maintenance

state, a DMV11 receives and transmits only maintenance messages. A maintenance message is formatted

much like a data message. It is formed by an eight-byte header followed by a variable length message
body. The content of the body is determined by the user program. Maintenance messages may consist of:

1) operating or diagnostic programs transmitted by the control station for down-line loading into the CPU
of a specified tributary, or 2) a portion of the contents of a tributary’s CPU memory as requested by the

control station. The request of this information is also handled by a maintenance message.

1.8 GENERAL SPECIFICATIONS
Environmental, electrical, and performance specifications for all DMV11 configurations are listed in
Sections 1.8.1 through 1.8.3.
1.8.1
Environmental Specifications
The DMVI1 is designed to operate in a class C environment as specified by DEC STD 102 (extended).

Operating Temperature

5°C (41°F) to 50°C (122°F)

Relative Humidity

10% to 90% with a maximum wet bulb temperature of 28°C (82°F) and a minimum dew point
2°C (36°F).

1-7

1.8.2

Electrical Specifications

The DMV11 requires the following voltages from the LSI-11 bus for proper operation.
Option

Voltage

DMV1I-M

+5SV@d4TA
+12 V. @ 0.380 A

DMVI11-N

+5SV@dd A
+12 V@ 0.260 A

A —12 V @ 250 mA required by the level conversion logic for both versions is generated off the +12 V by
a switching inverter.
1.8.3 Performance Specifications
Performance parameters are as follows:

—

Operating mode

Full- or half-duplex

—

Data format

Synchronous DDCMP

—

Data rates

Up to 56K b/s

—

Tributaries supported

Up to 12

DMVI1ls may be connected to DMP11s/DMVI1ls, DMR11s, DMClls, and any other synchronous
controller running DDCMP protocol.

1-8

CHAPTER 2
INSTALLATION

2.1
INTRODUCTION
This chapter provides all the information necessary for a successfu

l installation and subsequent checkout
of the DMV11. Included are instructions for unpacking and inspection
, preinstallation, installation, and
verification of operation.

2.2 UNPACKING AND INSPECTION
The DMV11 is packaged according to commercial packing practices.
When unpacking, remove all
packing material and check the equipment against the packing list.
Inspect all parts and carefully inspect
the module for cracks, loose components, and separations in the
etched paths. Report damages or
shortages to the shipper and notify the DIGITAL representative. .

2.3 INSTALLATION CONSIDERATIONS
Installation of the DMV11 microcontroller/line unit subsystem should
be done in
®

three phases:

Phase I - Preinstallation considerations

Verify system requirements, system placement, and configuration

requirements.

Network topology chart
For multipoint networks it is absolutely necessary to know the
configuration of the DMV11
(that is; control tributary, HDX, FDX, and so on) locations of tributarie
s (w/address), and
where in the network they are connected (control, Trib 187, Trib
98, Trib 208) or else
troubleshooting will be extremely difficult.
®

Phase Il - Microcontroller/line unit installation

Configure, install, and verify the microcontroller/line unit module
via the appropriate
diagnostics.
®

Phase IIl - DMV11 system testing

Verify the DMV11 microprocessor subsystem operation with the
functional diagnostics and

system exerciser programs.

2.4

PREINSTALLATION CONSIDERATIONS
The following should be considered prior to ordering a DMV11 communic
ations interface to ensure that
the system can accept the DMV11 and that it can be installed correctly.
The steps should also be verified
at installation time.
It is strongly recommended that a topology diagram be drawn
at installation time and maintained
throughout the life of the installation. Figure 2-1 shows a local network
topology and Figure 2-2 shows a
remote network topology.

2-1

—

]

ELEVATOR SHAFT

RX | TX
DELTA

11/70
DMP11

TRIB 3

SUSPENDED CEILING

RSTS XX.X

DE - XX.X

/ .y,

ROOM 515

]
|

wi=

]
2|
!

RX_| TX

RX | TX

GAMA
11/23
DMV 11
TRIB 2
RSX 11 M
DM - XX.X

BETA
11/34
DMP 11
TRIB 1
RSX11 M
DM - XX.X

1
|

ROOM 412

ROOM 430

—

RX |

ALPHA

VAX 11/780
DMP 11

CONTROL
X
VMS XX.

DV - XX.X
ROOM 111
MK-2502

Local Network Topology

MERRIMACK

VAX 11/780
VAX VMS XXX

DV-XX.X

*NOTE
1

*NOTE
2
CONTROL

*NOTE1
PATCH PANELS ARE

RECOMMENDED BUT MAY

NASHUA

NOT ALWAYS
BE USED.IF THEY

ARE USED, THEIR PHYSICAL

LOCATION SHOULD BE

4800

INDICATED.

11/60

| NASHUA

4800

EXCHANGE

RSTS XX.X

DE-XX.X

*NOTE
1
*NOTE
3

*NOTE
2
MODEM - 208A

TRIB 1

CONTROL STATION OPTIONS
SEE TABLE 2-1

*NOTE
3
MODEM - 208A

TEWKSBURY

]

TRIBUTARY OPTIONS

SEE TABLE 2-2

LOWELL

EXCHANGE

VAX 11/750

VAX VMS XX.X
DV-XX.X

*NOTE
1
*NOTE
3
TRIB
2
4800

| MAYNARD |

4800

EXCHANGE
MARLBORO

4800

11/23
RSX-11M
V.3.2

MARLBORO

DM XX.X

D MAYNARD

EXCHANGE

*NOTE
1

*NOTE
3

11/23
TRIB 4

RSX-11M

V.3.2

*¥NOTE
1

*NOTE
3
TRIB
3

MKV86-1662

Figure 2-2

Remote Network Topology

2-3

Typical Host Options of a Bell 208ATM Data Set (4800 b/s)

Table 2-1

Full-Duplex Operation

Data Set Options

DEC Recommended Settings

Transmitter timing

Data set (internal)

Carrier control

Switched

Request-to-send operation in
continuous carrier mode

Switched

One second holdover at
receiver on line dropouts

Not provided

New sync-option to squelch
receiver clock

Not used — NS is strapped OFF

Data set ready lead option
for analog loopback testing
by data terminal

within the data set

CC is ON when the AL button (only)
is depressed

Bell 208ATM is a trademark of Western Electric.

Table 2-2

Typical Tributary Options of a Bell 208ATM Data Set (4800 b/s)
Full-Duplex Operation

Data Set Options

DEC Recommended Settings

Transmitter timing

Data set (internal)

Carrier control

Switched (48.5 ms CA-CB delay)

Request-to-send operation in
continuous carrier mode

Switched (8 ms +.5 CA-CB delay; 0-35
ms depending on distance) N/A

One second holdover at
receiver on line dropouts

Not provided

New sync-option to squelch
receiver clock

Not used — NS is strapped OFF
within the data set

Data set ready lead option
for analog loopback testing
by data terminal

CC is ON when the AL button (only)
is depressed

The topology diagram should provide the following information.

Cable routing —

Show the actual physical location of the cable trough and
indicate any equipment which might cause interference
such as an X-ray room.

Machine type -

Indicate whether the CPU is a PDP-11/23, PDP-11 /70,
PDP-11/34, VAX-11/780, and so forth. (The network
could consist of a mixture of DMP11s and DMV11s).

Type of station —

Indicate if the station is a control or tributary station.

Physical address -

DDCMP address can range from 1-255.

Location —

Indicate by room number or other appropriate means, the
actual physical location of the equipment.

Node name —

The name given to the tributary if applicable.

Operating system and
version —

The name of the software operating system such as RSX11M V3.2,

DECnet version —

DEChnet software version such as DECnet-11M V3.0.

Transmit and receive —

Show transmit and receive lines. Depict end nodes and
show termination. If a patch panel is used, indicate the
line numbers between patch panels.

NOTE
The use of patch panels and numbering of the lines is
recommended.

2.4.1
Device Placement
The DMVII can be installed in any LSI-11 bus-compatible backplane such as H9276.
On systems that
contain many high-speed direct memory access (DMA) devices, there is a probability
of adverse bus
latency. To help prevent against this occurrence, the DMV11 should be placed physically
close to the
processor. As a result, this gives the DMV11 a high DMA priority.

2.4.2

System Requirements
e

LSI-11 bus loading

The M8053-MA or M8064-MA present two ac loads and one dc load to the LSI-11 bus.
®

Power requirements

Check the power supply before and after installing the microcontroller/line unit to ensure
against overloading. Power requirements are listed in Table 2-3.
®

Interrupt priority

The interrupt priority is preset to level four.

2-5

Device address assignment

The DMV11 address resides in the floating address space of the LSI-11 bus addresses. The
ranking assignment of the DMV11 for bus address is 24. (See Appendix B to determine the
proper bus address.)

The selection of the device address is accomplished by switchpacks on the microcontroller/line
unit module. Refer to Figures 2-3 and 2-4.

Device vector address assignment

The DMV vectors reside in the floating vector space of the LSI-11 bus addresses. The
ranking assignment of the DMVI11 for vector assignments is 46. (See Appendix B.)
The selection of the vector address is accomplished by a switchpack on the microcontroller/line
unit module. Refer to Figures 2-3 and 2-4.

Table 2-3

DMV11 Voltage Chart

Maximum

Minimum

Backplane

Module

Voltage Rating

Voltage

MB8053-MA

+5V @47A
+12V @ 0.380 A

+5.25
+12.60

+5.0
+11.40

AA2
AD2

M8064-MA

+5V @44 A
+12 V@ 0.260 A

+5.25
+12.60

+5.0
+11.40

AA2
AD2

2-6

M8053

E54

E53

|
MK-2698

Figure 2-3

MS8053 Switch Locations

2-7

XTI

]
T

[
ens
|| E107
|

M8064

E59
E58

]

f
MK-2521

Figure 2-4

M8064 Switch Locations

2-8

2.5

INSTALLATION
LSI-11 configuration rules must be followed when installing the DMV11 in the LSI-11 bus-compatib
le
backplane. When installing the DMV 11-SF (BA200 series enclosure), refer to Sections 2.7 through 2.14.
Proceed with the installation as follows by performing the following on the slot that will contain
the

DMV11.

Using the flowchart in Figure 2-5, verify that the switch selectable features of the DMV11 are
configured for the station being installed. Figure 2-6 and Tables 2-6 and 4-5 show switch
selectable features.

Insert the appropriate module test connector (H3255 and/or H3254) into the correct microcontroller/line unit connectors. Be sure to insert the test connector with “SIDE 1” (etched on the
test connector) visible from the component side of the module. Refer to Figures 2-7 and 2-8.

o
(¢

-y

Configure the correct vector address (as determined from Appendix B) using switchpack
settings from Table 2-5.

O
o=

Configure the correct device address (as determined from Appendix
settings from Table 2-4.

Turn system power OFF.
gQ

N’

Verify that the backplane voltages are within the tolerances specified in Table 2-3.

Schematics and outline drawings of each test connector used with the DMV11 are provided in
Figure 2-9.

Install the DMVI11 and perform resistance checks on the backplane voltage source to ground.
This ensures that no short circuits exist. Refer to Table 2-3 for backplane pin assignments.

Turn system power ON and repeat Step 1.

Load and execute the DMV11 static diagnostics. Five error-free passes of each part is the
minimum for successful operation.

(C)VDMA** — DMV11 static logic test part 1
(C)VDMB** - DMV11 static logic test part 2

(C)VDMC** - DMV11 static logic test part 3
(C)VDMD** - DMV11 static logic test part 4
(C)VDME** - DMV11 static logic test part 5
10.

Remove the module turnaround test connector and connect the appropriate cable (see
Table 2-7
and Figures 2-10 and 2-11) to the proper BergTM connector for the DMV11 option selected.
Refer to Table 2-7 for detailed information on cable requirements and to Figures 2-12 through
2-16 for system cabling configurations.

NOTE
When installing panel cables 70-20861, 70-20862,
70-20863, or 70-20864, it is important that the
panel be properly mounted to the rear-mounting
bulkhead

to
Figure 2-17).

ensure

adequate

BergTM is a trademark of Berg Electronics.

2-9

grounding

(see

When connecting the 70-20863 connector panel, verify that the appropriate modem switches on
the panel are properly configured for the option selected (see Figure 2-18). Table 2-8 lists each
of these options and required switch configurations. When connecting the BC55H interface
panel, refer to Table 2-9 for options and required jumper configurations.

Integral modem options require that a 75 ohms terminator be connected to each receive line
(70-20862 panel) at each end of a full-duplex and half-duplex network. Refer to Figure 2-11 for
DMV11 remote cabling and to Figure 2-12 for DMV11 to DMV11 local cabling.

Insert the appropriate cable turnaround test connector in the end of the cable. Refer to Table
2-7 for the specific test connector. Load and execute the static diagnostics specified in Step 9
using the external maintenance mode selected to verify the module and cable. Upon obtaining a
minimum of five error-free passes, proceed to the DMV 11 system test procedures (Section 2.6).
Figure 2-9 illustrates the various test connectors used in the DMV11.

Loopback testing on the integrated modem panel is performed by SW1. Depress SW1 IN for
loopback to module testing. Return SW1 to the OUT position when diagnostic testing is
completed.

Table 2-4
MS B

1 | «——— M8053 E53 M8064 E 58 ——>{ M8053 | o0 | 0 | ©

]
!

SWITCH
NUMBER

]

S8 ] S7 | S6|

]S4

Eb4

I
]

]
i

|
i

i
]

|
]

|
|

|
(]

S3]S2

mso64
E59

DEVICE

ADDRESS

760020

760040

ON | ON

760060

ON | ON

!
]

S1 | S2

760100

ON
ON
ON
ON | ON
ON | ON | ON

760200

7652:}00

7661-100
766é00
765600
76(-)-;00
76:I_(-)OO

76-2-(-)00
76(-3-(.)00

ON
ON | ON
ON

764000

NOTE 1:

SWITCH ON RESPONDS TO LOGICAL ONE ON THE BUS

NOTE 2:

S1 (M8053-E54 AND M8064-E59) IN UNUSED.

NOTE 3:

4‘3

12]11|1019|Sl716l5

15]14 13
1

Device Address Selection

UNUSED

11.

DEVICEADDRESS MUSTHAVE BIT3=0(ONLYADDRESSESENDINGINOO, 20,40
OR 60 CAN BE USED).
MKVEE-1867

2-10

Table 2-5

Vector Address Selection

MSB

LSB

15[14

12'11

9|8

olo

MBO53 E54

.l‘

[1/0

M8064 E59

6'5

3[2

]

SWITCH

NUMBER

1 ] o

S8 | S7|s6 ) s5|s4]s3
on | oN

300

on | oN

VECTOR

ADDRESS

oN | oN

310

on | oN
ON | ON § ON

320

ON | ON

330
340

on ] on | on
ON
on | on | on | on
on | on]on|on|on

350
360
370
400

500

oN | ON

800

on | on | on

700

NOTE: SWITCH ON PRODUCES LOGICAL ONE ON BUS
MK-2683

2-11

THE FOLLOWING PROCEDURES USE EITHER SWITCHPACK E101 ON THE M8053 MODULE,
OR SWITCHPACK E107 ON THE M8064 MODULE

(SWITCH OFF =1

SWITCH ON =0
DEFAULT IS 0)
IS THE

DMV11 CONNECTED
TO A MODEM ON

SET SW3
ON

A SWITCHED
LINE

SET SW3
OFF

IS THIS

SET SW1

SYSTEM TO BE

OFF

DOWN-LINE
LOADED

SET SWi1
ON

SET SW2

OFF

NO
\

LINE SPEED

INTEGRAL MODEM

19.2K b/s

USED OR IS THE LINE SPEED
GREATER THAN

SET SW9

19.2K b/s
INTEGRAL
MODEM

SET SW9
OFF

MKV86-1681

RS-232-C
OR R$-422
INTERFACE

IS THIS
SYSTEM TO

SET Sw4

BE DOWN-LINE

LOADED ON

RS-422

SET SW10
ON

POWERUP

SET SW10
SET sw4

OFF

(
IS THIS

SYSTEM TO

END

)

SET SW5H

BE DOWN-LINE

LOADED BY

JTHE HOST

SET SW5
OFF

CONFIGURE Sws,

SW7 & SW8 AS

SHOWN IN

FIGURE 2-6

L
MKV86-1682

Figure 2-5

DMV11 Installation Flow (Sheet 2 of 3)

2-13

THE FOLLOWING PROCEDURES USE EITHER SWITCHPACK E113 ON THE M8053 MODULE,

OR SWITCHPACK E119 ON THE M8064 MODULE.

START

SET SWi1

IS A

POINT-TO-POINT

NO (MULTIPOINT)

LINK TO BE

THROUGH Sw8
>

TO TRIBUTARY
NUMBER.

OFF=1, ON=0

SET SW1 OFF

SET SW2
THROUGH SW8
ON

MKV86-1683

Figure 2-5

DMV11 Installation Flow (Sheet 3 of 3)

2-14

——MODE DEFINED BY SW6, 7, 8, ENABLED OFF
—UNIT NUMBER FOR BOOTING, UNIT O = ON, UNIT 1 = OFF

——AUTO ANSWER, ENABLED ON
——POWER ON BOOT, ENABLED OFF

T—REMOTE LOAD DETECT, ENABLED OFF
DDCMP ADDRESS REGISTER

TRIBUTARY/PASSWORD

INTERFACE SELECT

AN—

T T7 ¥

E113

E101

MB8053

E119

E107

MB064

SW 10

|MODULE

CCITT V.35

M8053

[£1A RS 232-C/RS-423.A|

OFF | M8053

INTEGRAL MODEM

UNUSED | M8064

HIGH-SPEED SWITCH

SW9
M8053

M8064

BAUD RATE < 19.2K b/s

BAUD RATE 19.2K b/s OR|

OFF

GREATER

NOTE M8064 SW 9 ALWAYS OFF

M8053

SWITCH
MODE DEFINITION

HDX PT-TO-PT/DMC LINE COMPATIBLE { ON | ON | ON
FDX PT-TO-PT/DMC LINE COMPATIBLE

I l

I"L

HDX PT-TO-PT

rrl

FDX FT-TO-PT

| OFF|

ON | ON

ON | OFF | ON

OFF | OFF | ON

HDX MULTIPOINT CONTROL STATION | ON | ON | OFF

FDX MULTIPOINT CONTROL STATION

| OFF|

ON | OFF

HDX MULTIPOINT TRIBUTARY

ON | OFF | OFF

FDX MULTIPOINT TRIBUTARY

OFF | OFF | OFF
MKV86-1664

Figure 2-6

DMV11 Switch Selectable Features

2-15

Table 2-6

DMV11 E101 (M8053)/E107 (M8064) Switch Selectable Features

Switch
Number

Switch
Name

Switch Position
when Function
is Enabled

]

MODE ENABLE

OFF

DMV11 Function/Description
when Switch is Enabled

Indicates that the DMV11 mode of operation is defined in switches 6, 7, and 8. If
disabled, mode of operation must be
software assigned.

UNIT NUMBER
FOR BOOTING

Defines which DMV11 is performing the
remote boot if two DMVI11 options are
installed on the same LSI-11 bus. This
switch offers the selection of:

ON or OFF

Unit Number Zero = “ON”
Unit Number One = “OFF”
AUTO ANSWER

Causes the DMV11 to assert DTR and
wait for modem ready (DSR). DSR is the
indication that the call has been estab-

OFF

lished. This sequence allows the DMV11
to automatically answer all incoming calls
to the LSI-11 computer station. If a valid
DDCMP message is not received within
30 seconds after a connection is established, DTR is dropped (hang up the
telephone).

POWER-ON
BOOT ENABLE

Allows the power-on boot feature at the
remote/tributary station. The node which
is to receive the boot requests the host
station to start the primary MOP boot
procedure. The BOOT request is sent out
when the first poll message after the
remote station’s power-up sequence 1is

OFF

complete.

REMOTE LOAD
DETECT ENABLE

Allows the remote load detect boot feature at the remote/tributary station. The
host node starts the booting sequence by
starting the primary MOP boot

OFF

procedures.

6,7,8

MODE OF
OPERATION

ON or OFF
(as applicable)

These three switches define the DMVl
module’s mode of operation, at device
boot (initialization) time, if switch 1 is set
to the “OFF” position. Refer to Table 4-5
for a listing of the different switch positions and the operating modes they
define.

2-16

Table 2-6

DMV11 E101 (M8053)/E107 (M8064) Switch Selectable Features

(Cont)

Switch Position

Switch

Number

Name

is Enabled

HIGH SPEED

OFF

when Function

DMV11 Function/Description

when Switch is Enabled

Selects the baud-rate that the DMV1]
operates at:

HIGH SPEED = “OFF” = 19.2K b/s
and greater

LOW SPEED = “ON” = <19.2K b/s

NOTE
The integral modem (M8064) requires switch 9 to be
set to the enabled (“OFF”) position.

INTERFACE
SELECT

ON or OFF

“ON” =

CCITT V.35 modem interface selected.

“OFF” =

EIA RS-232-C or RS-423-A
modem interfaces selected.

NOTE
Switch 10 is not used with the M8064 (integral
modem) DMV11-N option.

2-17

Table 2-7

Cabinet Kits

Cabinet
Kit

Description

CK-DMVII1-AA

Cabinet kit for EIA RS-232-C with 53.34 cm (21 inch) cable for PDP-11/23S

CK-DMVI1-AB

Cabinet kit for EIA RS-232-C with 30.48 c¢cm (12 inch) cable for Micro-11

CK-DMV11-AC

Cabinet kit for EIA RS-232-C with 76.20 cm (30 inch) cable for PDP-11/23+

CK-DMV11-A2

Cabinet kit for (non-FCC compliant) EIA RS-232-C with 91.44 cm (36 inch)
cable for unshielded cabinets containing H349 mounting panel, BC55H-03 cable,

70-20863-00 panel, H325 test connector, and BCO08S-1K cable.
70-20863-00 panel, H325 test connector, and BCO8S-01 cable.

70-20863-00 panel, H325 test connector, and BCO8S-2F cable.

and H325 and H3251 test connectors.

CK-DMVI1I1-BA

Cabinet kit for V.35 with 53.34 cm (21 inch) cable for PDP-11/23S 70-20861-1K

CK-DMV11-BB

Cabinet kit for V.35 with 30.48 cm (12 inch) cable for Micro-11 70-20861-01
panel, H3250 test connector, and BC17E cable.

CK-DMV11-BC

Cabinet kit for V.35 with 76.20 cm (30 inch) cable for PDP-11/23+ 70-20861-2F

CK-DMV11-B3

Cabinet kit for (non-FCC compliant) V.35 with 7.62 m (25 feet) cable for
unshielded cabinets containing H349 mounting panel, BCO5Z-25 cable, and

panel, H3250 test connector, and BC17E cable.

panel, H3250 test connector, and BCI7E cable.

H3250 test connector.

CK-DMV11-CA

Cabinet kit for integral modem with 53.34 cm (21 inch) cable for PDP-1 1/23S
70-20862-00 panel, H8568 and H8570 test connectors, and 70-18250-1K cable.

CK-DMV11-CB

Cabinet kit for integral modem with 30.48 cm (12 inch) cable for Micro-11

CK-DMV11-CC

Cabinet kit for integral modem with 76.20 cm (30 inch) cable for PDP-1 1/23+
70-20862-00 panel, H8568 and H8570 test connectors and 70-18250-2F cable.

CK-DMV11i-C3

Cabinet kit for (non-FCC compliant) integral modem with 91.44 cm (36 inch)
cable for unshielded cabinets containing H349 mounting panel, BC55F-03 cable,

70-20862-00 panel, H8568 and H8570 test connectors, and 70-18250-01 cable.

and H3257 and H3258 terminators.

CK-DMVI11-FA

Cabinet kit for RS-423-A/449 with 53.34 cm (21 inch) cable for PDP-1 1/23S

CK-DMV11-FB

Cabinet kit for RS-423-A/449 with 30.48 cm (12 inch) cable for Micro-11

CK-DMV11-FC

Cabinet kit for RS-423-A /449 with 76.20 cm (30 inch) cable for PDP-11/23+

CK-DMV11-F3

Cabinet kit for (non-FCC compliant) EIA RS-423-A/449 with 91.44 cm (36
inch) cable for unshielded cabinets containing H349 mounting panel, BC55H-03

70-20864-00 panel, H3251 test connector and BCO8S-1K cable.

70-20864-00 panel, H3251 test connector, and BC08S-01 cable.

70-20864-00 panel, H3251 test connector, and BCO8S-2F cable.

cable, and H325 and H3251 test connectors.

NOTE 1:

Refer to Appendix E for more cabinet kit information.
NOTE 2:

MicroVAX uses same cabinet kit as the Micro-11.

2-18

CONNECT CABLE 70-20861

FOR V.35 INTERFACE

1‘
H3254

TEST CONNECTOR |

H3255

TEST CONNECTOR|

2 | [T~
J2

CONNECT CABLE BCO8S

FOR RS-232-C OR RS-423-A

M8053

INTERFACE.

L
MKV86-1665

Figure 2-7

Test Connector Insertion for the M8053

CONNECT 70-18250
FOR INTEGRAL MODEM

H3254

TEST CONNECTOR

i 3QIS

M8064

MK-2699

Figure 2-8

Test Connector Insertion for the M8064

2-20

—

TXCLK +

—

RECCLK -

—_—

TXCLK -

———

TX DATA -

——

R DATA +

—

TX DATA +

DATA MODE
TXINT

RECINT
TXINT

REC INT

SIDE 1
H3254

VIEW
A
H3254 MODULE TEST CONNECTOR (J1 ON M8053/M8064)
MK-2645

AUX CLK + —p——
TX CLK DIFF ¢ ——a——

RX CLK DIFF 4 ——a—
AUX CLK —

TX CLK DIFF =

k.
-

RX CLK DIFF = —a—
TX DATA DIFF +

RX DATA DIFF +
TX DATA DIFF -

RX DATA DIFF -

RTS

CTS
CDET
VIEWB

DTR

DSR

H3250

pm}xlmlo 0*40m?m v*x9m¢21<l< ej)

TER RDY

REC RDY

CTS

RTS

—

R DATA

NULL CLK -

RECCLK +

—

0§0T,Q§+:: N IS 2 BT 33 X Ya¥ 127 g 6:13%”'“‘[ Io] B +'1°> r

NULL CLK +

—

MK-2123

Figure 2-9

DMVI11 Test Connectors (Sheet 1 of 4)

2-21

SEND COMMON
REC COMMON

TER IN SER

HRNEEEN

—_————e

INCOMING CALL
TER RDY

DSR

SEND DATA +

REC DATA +

SEND DATA REC DATA NULL CLK +

SEND TIMING +

REC TIMING +

NULL CLK —

CTS +

REC RDY +

SIGNAL RATE IND

SEL SIGNAL RATE

% SEC SEND DATA

SIGNAL QUALITY

NEW SIGNAL

% SEC REC DATA

* SEC RTS

TEST MODE

’

SEL STAND BY

LOCAL LOOP

* SEC CTS

REC RDY —

CTS —

DSR —

RTS —

STAND BY IND

TER RDY —

X NOT REQUIRED FOR DMV11

+
+

SIDE 1

ERERERERERE

RTS +

TH1

TH2

H3255

VIEW C

H3255 MODULE TEST CONNECTOR (J2 ON M8053)

REC TIMING —

( = C+I.% o & gmexboovrg0E0<0£0§#§#$¢—11<9

SEND TIMING —

MKV86-1666

Figure 2-5

DMV 1L
TM

ANy

Vel

1CSL LONNICCLOIS WICCL £ VI

2-22

SIGNAL RATE INDICATION

—=

-—

SHIELD GROUND

Ké\
1
e

SEND DATA +

SEND TIMING +
REQ DATA +

——T1¢
>

REQ TO SEND +
REQ TIMING +

——T18

CLEAR TO SEND
+

LOCAL LOOP

DATA MODE +

102

TERMINAL READY +

RECEIVER READY +

REMOTE LOOP

SIGNAL RATE SEL

TEST MODE

TERMINAL TIMING +

SIGNAL GROUND
RECE!VE COMMON

107

.
‘220:)

2‘2

——

REQ TIMING
-

——1

DATA MODE-

‘;;%

]

SELECT STANDBY
SIGNAL QUALITY

_4-__&_:]

NEW SIGNAL

STANDBY INDICATION

SEND COMMON

—.——2‘:23

TERMINAL TIMING-

——T2
~ ——"t—@

TERMINAL READY-

RECEIVER READY
-

REQ TO SEND-

§§ 20

§§

—4—-—2t5

REQ DATA-

CLEAR TO SEND-

——

SEND TIMING

TERMINAL IN SERVICE

]

—4——?4

INCOMING CALL

SEND DATA

H3251

——

VIEW D

—-——zcz
-

-y

H3251

CABLE TEST CONNNECTOR

MK-2746

Figure 2-9

DMV11 Test Connectors (Sheet 3 of 4)

2-23

H325

SOT et
oos
SEC XM|T =t
CUT TO TEST
NEW

SIDE

+SYNC

1 s

XMIT DATA:j

RCV DATA

CS—‘—-L
NEW SYNC—

14
H326

DATA SET RDY o
CUT TO TEST*
NEW SYNC

DTR

VIEW E

H3256 CABLE TEST CONNECTOR
MK-2124

Figure 2-9

DMV11 Test Connectors (Sheet 4 of 4)

2-24

VIEW A

40-PIN SOCKET

D
J

40-PIN SOCKET

c _>|

|<— D

F
J

E
H

T
v

X
Z

Y]
H_

BB[
| JAA
FF

LL3

NI
R

J |L

X
Z

w
Y

LL3

—i

BCO8S (RS-232-C/V.35/RS-423-A, RS-449 INTERFACE) PANEL CABLE
TK-11009

‘0000N00000000
000000000000

VIEW B

25 PIN

CONN.

CONN.
BC22F-10 (RS-232-C INTERFACE) MODEM CABLE

TK-11010

0000000 00000C0000000
Q0 0000Q 00000000000

VIEW C

BC55D-33 (RS-423-A/449 INTERFACE)MODEM CABLE
TK-11011

Figure 2-10

DMV11 Cable Drawings (Sheet 1 of 3)

2-25

00000000000 0000000

000000000000 0000000

VIEW D

37 PIN

CONN.

BC17E (V.35 INTERFACE) MODEM CABLE

TK-11012

—

d
Iy

({11}

VIEW E

BCE6D TWINAX CABLE (WITH FEMALE CONNECTOR)
NOTE:

BC56A CABLE IS SIMILAR TO BC56D AND BC56B CABLE IS
SIMILAR TO BC56E, EXCEPT BOTH USE TRIAX CONDUCTORS
RATHER THAN TWINAX. ALL USE H8568 AS AN ADAPTOR.

PN A

BC56E TWINAX CABLE (WITH MALE CONNECTOR)
TK-11013

VIEW F

PI 4
BC55T TWINAX CABLE
NOTE:

BC55S CABLE IS SIMILAR TO BC55T CABLE, EXCEPT
USES TRIAX CONDUCTOR RATHER THAN TWINAX. BOTH ALSO
USE H8568 AS AN ADAPTOR.
TK-11014

Figure 2-10

DMV11 Cable Drawings (Sheet 2 of 3)

2-26

VIEW G
/ 70-20862
70-18250

S— m]

70-20862

CONNECTOR PANEL
(FRONT VIEW)
70-18250 (INTEGRAL MODEM)PANEL CABLE

NOTE:

TYPE OF DUPLEX OPERATION MUST ALWAYS BE ESTABLISHED
BY VIEWING CONNECTOR MATING FROM SIDE 2 (REAR
SIDE OF 70-20862 ASSY, OR SAME SIDE AS SWITCH S1).
HALF (BLUE) SIDE OF CONNECTOR FACING VIEWER PROVIDES HALF:
FULL (RED) SIDE OF CONNECTOR FACING VIEWER PROVIDES FULL.
MKV86-1667

VIEW
H

T
A

/IS

Cal

H8568

H8570

TEST CONNECTOR

TERMINATOR
TK-11016

3 £

70-20861

I{TTTITY

VIEW |

PANEL CABLE

MKV86-1669

Figure 2-10

DMV11 Cable Drawings (Sheet 3 of 3)

2-27

A
VIEW

RS-423-A

RS-232-C

BC55H (RS-232-C/RS-423-A) INTERFACE PANEL CABLE
MKV86-1678

e
O |/e
x| @lololole|o|olelo|o|ole|e|ee

=w< m

0nO€®eF

IRW
-]
w T o8 I Z o W8] i w L

BCO52-25 (V.35 INTERFACE) MODEM CABLE

* INDICATES CAVITIES USED TO
MOUNT STRAIN RELIEF
MKV86-1679

Figure 2-11

DMV11 Non-FCC Compliant Cable Drawings (Sheet 1 of 2)

2-28

VIEW C

FEMALE CONNECTORS

ou 7/‘OUT
P4

HDX

RECElVE@ TRANSMIT

E[[H]I[I]]]]IIII]]IIIEI

PTW_
fifz
BCS55F (INTEGRAL MODEM) PANEL CABLE

MALE CONNECTORS

CONNECTOR PANEL
(FRONT VIEW)

VIEW D

—
—

———\

—
—
|—

—

H3258

H3257

TERMINATOR

(FEMALE)

(MALE)

MKV86-1680

Figure 2-11

DMV11 Non-FCC Compliant Cable Drawings (Sheet 2 of 2)

2-29

RS-232-C INTERFACE

BCO8S

CABLE

]

MODEM

D S2

(

6-10

53
11-15
S s4

\{J1

V8053

S 16;20

J2 TEST

CONNECTOR

H325 TEST

CONNECTOR

H3255

—_—

BC22E OR BC22F CABLE

DMV1 1-R°S-232

70-20863
PANEL

V.35 INTERFACE
BC17E CABLE

70-20861
PANEL
-

BCOBS

ALl
AB

CABLE

EA%SDEM

H3250 TEST

CONNECTOR

M8053

J1 TEST

CONNECTOR

H3254

RS-423-A/449 INTERFACE
BC55D CABLE

BCO8S

CABLE

—]

J2 TEST

M8053

\\ CONNECTOR
.

A OS 237

DMV11-RS-4

MODEM

J2RNJ?

pondl

[J1

H3255

H3251 TEST

CONNECTOR

70-20864

PANEL
MKV86-1668

Figure 2-12

DMV11 Remote Systemn Cabling Diagram (Sheet 1 of 2, FCC Compliant)

2-30

RS-232-C/423-A

H325

(RS-232-C)

J1
BC55H

]

un/

BCO5D

MODEM

(7
=b =
12

BC55H
'\
PANEL

X_J1

M8053
AL

\\\\JZ TEST
J

NOTE:

CONNECTOR

BC55D

RS-423-A
H3251 (RS-423-A)

H3251 (BC55D)
H325 (BCO5D)

H3255

BC55H CAN ONLY BE INSTALLED IN SYSTEMS BUILT IN 1982 OR LATER THAT
CONTAIN AN H349 MOUNTING PANEL. OLDER SYSTEMS NOT CONTAINING AN
H349 MOUNTING PANEL CAN USE BC55C IN PLACE OF BC55H.

V.35 INTERFACE

(r
&=
J2

BCO5Z-25
\\\\\\J1 TEST

MODEM

CABLE TEST

CONNECTOR

M8053

V.35

H3254

CONNECTOR
H3250

A
MKV86-1670

Figure 2-12

DMVI11 Remote System Cabling Diagram (Sheet 2 of 2, Non-FCC Compliant)

2-31

FULL-DUPLEX

INSTALL 75%
TERMINATOR

CONNECTOR (H8570)
IN J2

-'/

70-20862

G eessr
hd

RSk J4

PANEL

s P

Poanmn P

M8064

—
——————

LIV

M8064

’

70-18250

BC55T

70-20862

INSTALL 759

PANEL

TERMINATOR
CONNECTOR

70-18250

(H8570) IN J2

HALF-DUPLEX

INSTALL 752
TERMINATOR

CONNECTOR (H8570)
70-18250

IN J3

M8064

2" )

BC55T

7
70-20862

INSTALL 75Q

PANEL

TERMINATOR

CONNECTOR (H8570)
IN J4

70-18250

NOTES:

TYPE OF DUPLEX OPERATION MUST ALWAYS BE ESTABLISHED
BY VIEWING CONNECTOR MATING FROM SIDE 2 (REAR

SIDE OF 70-20862 ASSY, OR SAME SIDE AS SWITCH S1).

HALF (BLUE) SIDE OF CONNECTOR FACING VIEWER PROVIDES HALF;
FULL (RED) SIDE OF CONNECTOR FACING VIEWER PROVIDES FULL.
MKV86-1671

Figure 2-13

DMVI11 to DMVI1 Integral (Local) Modem Cabling Diagram (Point-to-Point)

(Sheet 1 of 2, FCC Compliant)

2-32

FULL-DUPLEX

fi
QA
1

INSTALL 750
TERMINATOR

BC55F

CONNECTOR (H3257)

M8064
HDX/FDX SWITCH
MUST BE IN THE FDX
(down) POSITION ON

M8064

BC55F

INSTALL 75Q
TERMINATOR
CONNECTOR

(H3258)

HALF-DUPLEX

INSTALL 759

()

TERMINATOR
CONNECTOR (H3257)

BC55F

HDX/FDX SWITCH
MUST BE IN THE
HDX (up) POSITION

ON BOTH PANELS
M8064

|
BC55F

INSTALL 75%Q
TERMINATOR

CONNECTOR
(H3258)

FOR 56K b/s USE CABLE BC55N OR BC55D, BC55E, BC55T,
AND (2)

H8568.

NOTE:

BC55F CAN ONLY BE INSTALLED IN SYSTEMS BUILT IN 1982
OR LATER THAT CONTAIN AN H349 MOUNTING PANEL. OLDER

SYSTEMS NOT CONTAINING AN H249 MOUNTING PANEL CAN
USE BC55A IN PLACE OF BC55F.
MKV86-1672

Figure 2-13

DMVI11 to DMV11 Integral (Local) Modem Cabling Diagram (Point-to-Point)
(Sheet 2 of 2, Non-FCC Compliant)

2-33

HDX NETWORK

TERMINATOR

(H8570)

M8064

CONTROL

STATION

)

2
70-18250
|

70-20862

:’

PANEL

BCssT |

TRIBUTARY

: O

70-18250

7|
oX O@
RX
|

70-20862

(

PANEL

BCS5T |

TRIBUTARY

s
o

70-20862
PANEL

70-18250

BC55T

rTT T

l
I

TRIBUTARY

}

70-20862

TERMINATOR

PANEL

(H8570)
MKV86-1673

Figure 2-14

Half-Duplex Multipoint Network (Control Station End Node)

2-34

FDX NETWORK
TERMINATOR

70-20862

(H8570)

PANEL

CONTROL

STATION

70-18250

70-20862
PANEL

TRIBUTARY
lr .

IVO

70-18250

70-20862
PANEL

TRIBUTARY

\[ Mo ?o 70-18250
©

BC55T

I
|

|
70-20862
PANEL

TRIBUTARY

©]

[©]

70-18250

TERMINATOR

(H8570)
NOTES:
SOLID LINE REPRESENTS CONTROL STATION TRANSMIT TO

TRIBUTARY RECEIVE.

DASH LINE REPRESENTS CONTROL

STATION RECEIVE FROM

TRIBUTARY TRANSMIT.
BOTH ENDS OF THE TRANSMIT LINE FROM THE TRIBUTARIES NEED TERMINATION
IN ADDITION TO THE ONE TRANSMIT LINE FROM THE CONTROL STATION.
MKV86-1674

Figure 2-15

Full-Duplex Multipoint Network (Control Station End Node)

2-35

FDX NETWORK
TERMINATOR

70-20862

(H8570)
\

PANEL

TRIBUTARY

M8064

S©

;oka
©

70-18250

{

CONTROL

70-20862
PANEL

J2
T

STATION

‘
70-18250

| OR%
|

—

BC55T

70-20862
PANEL

|
S

’

TRIBUTARY
S

i
70-18250

=BC55T

TRIBUTARY

TERMINATOR

(H8570)
NOTES:

SOLID LINE REPRESENTS CONTROL STATION TRANSMIT TO

TRIBUTARY RECEIVE.

DASH LINE REPRESENTS CONTROL STATION RECEIVE FROM TRIBUTARY
TRANSMIT.

SINCE THE CONTROL STATION IS NOT AN END MODE THERE IS A NEED TO
TERMINATE TWO SETS OF TRANSMIT LINES FROM THE CONTROL STATION.
ADDITIONALLY BOTH ENDS OF THE TRANSMIT LINE FROM THE TRIBUTARIES.
MKV86-1675

2-36

70-20861-XX

FCC

BULKHEAD
(REAR VIEW)

FCC
BULKHEAD
(FRONT VIEW)

\
|

¢ oml]eo

20000

@©

@ o

@LLLflcb

‘@ o

70-20861-XX

/é)L

Fal

70-20862-01

&1@

72-20863-01

]@
70-20864-01

NOTE: ALL POSSIBLE CABINET KITS ARE SHOWN.
MKV86-1676

Figure 2-17

DMV11 Cabinet Installation to FCC Bulkhead

2-37

25 PIN

n A A 0 A 7 Y A A » \ A Y Y Y VY Y A

_ | | o o!l 1 "0"0. 0 0 01

ONOPOLROROEOPOZONOLO20T0TOTOTO2OR0KOFORQIO<O805

D SUBMINIATURE

_ |
o«

ouT

zZ%

MKV86-1677

Figure 2-18

DMV11 to RS-232-C Interface Panel (70-20863)

2-38

Table 2-8

5|81

3 | S2

Switch Function Settings on 70-20863 Panel for RS-232-C Interface

ON | ON[ON | ON

142

MAKE BUSY | 25

CC | 25|S3

{116]

RR|

{126

CH|SR|{111]

DA|

36|

RR|36|S7|ON

{10]S8

{14|S11/ON

113

[S14]/0ON

|S15

ON [ ON|ON|ON | ON

|ON

ON/ON;ON|ON|ON|ON|ON|ON|DD|RT|115]17
ON ! ON|ON|ON

ON|ON|ON|ON

SCAISRS|120]

| 12|S18{ON|ON|ON|ON|ON|ON|{ON|ON|ON|DB|ST

FF | 28

|113]

{S20

ON|{ON | ON|

|141]18
|114]|

RL|140|

NOTES:

1. ALL SWITCHES ARE OFF UNLESS SELECTED.

2. SWITCHES S3, S6, S7, S14, S15, AND S20 ARE CONNECTED TO A “DUMMY”
GENERATOR, WHICH

PROVIDES AN OFF STATE CONDITION TO THE INTERFACE

3. SWITCHES S5, S9, S10, S12, S13, S16, S17, AND S19 SHOULD ALL BE OFF.
MKV86-0894

2-39

Table 2-9

BC55H Jumper Modem Functions
@

40Q

N
&
Q\%\g@

QDS

V% 3

/S/S

V)V

)

NININ

/IS ) L

/S S
S NS/
S/S
S/S//)8
C/S/
NI/ T/S/S/S/S/S
SS
LY/
/S
/G
/S

g
&

N4
<

0,)\

ng /\&

NN/

S$
¢

Y Q

111

| IN

110

126

112

| IN

SBB

SRD

119

wé

| IN

SBA

SSD

118

SCF

SRR

| IN

140

v
N

4
15

W9 | IN
W10 | IN

[IN [ IN | IN
|IN | IN]IN|{IN
[IN
[IN { IN | IN [ IN]|IN|IN

|IN
|IN

CA
DB

RS
ST

105 | 7
114 | 5

R
K

17
18

w11
W12

[IN

SCA | SRS

115 | 8
141
10

W14

|IN

RT
LL

W15

W16 | IN

M
cC
D
C

25
24
13
25

W17
W18
w19 | IN
W20

w21

103

J
T

3
5

BB
CB

RD
CS

104 | 6
106 | 9

[IN

W13 | IN

JIN

[N
IN

TN
FINJININ
[IN | IN|IN

IN [ IN|IN]IN

NOT NORMALLY INSTALLED
IN

| IN

IN | IN | IN|IN

[ IN [ IN]IN

SCB
|IN | IN | IN

122

121

TM
TT

142 | 18
113 | 17

117 | 36

SS
116 | 32
SCS
121
28
MAKE BUSY

101

107

VvV
BB

108

109 |

1256 |

NOTES

All JUMPERS ARE OUT UNLESS SELECTED.

JUMPERS W3, W4, W8, W12, W13 AND W18 ARE CONNECTED TO A “DUMMY’" GENERATOR, WHICH PROVIDES AN

102

19
12

OFF STATE CONDITION TO THE INTERFACE.

JUMPERS W10, W11 AND W16 ARE IN FOR TESTING WITH
THE H325.
MKV86-1685

2-40

2.6 DMV11 SYSTEM TESTING
The final step in the installation of a DMV11 subsystem is to exercise
11 bus; and 2) a link in a communications network.

the DMV11

as: 1) a unit on the LSI-

2.6.1

Functional Diagnostic Testing
Ensure that the specific cable turnaround test connector for the selected

DMV 11 option is still installed at
the end of the cable. Load and execute the DMV 11 functional diagnosti
cs with the external mode selected.
Upon obtaining a minimum of five error-free end passes, proceed
to Section 2.6.2.

2.6.2

DEC/X11 System Exerciser

The DEC/X11

system exerciser for the DMV 11 can be run in two different operating
modes, internal and
external. The internal mode selects faster LSI-11 bus activity. The
external mode requires that the specific
modem test connector be installed at the end of the cable. This
is the preferred mode of operation. There
are two DEC/X11 modules for the DMV11; DMD* and DME*.

2.6.3 Final Cable Connections
The final step in the installation process is to return the DMV
11

to its normal cable connections, either to
the appropriate modem or to the distribution panel. The DMV11 system
cabling diagrams in Figures 2-12
through 2-16 have been included to help show overall cabling
for the various DMV11-XX options.
References to specified locations of the various test connectors during
diagnostic testing are also included.
After the cables are connected to the appropriate modem or distribut
ion panel, it is suggested that the data

communications link test program (DCLT) be exercised.

2.6.4 DMV11 Link Testing
The DMV11 can be exercised over a communications link by
the data communications link test (DCLT).
It is suggested that DCLT be configured to run first on a cable test
connector and then on a modem with
the modem analog loopback test feature selected (if the modem includes
this feature). Next, the overall
communications link should be exercised with the remote computer
system that contains a DMV11.

2.6.5 MDM Diagnostics
The perfomance of the DMV11 can be verified by running the MDM
(MicroVAX Diagnostic Monitor)
diagnostics. Refer to the following documents for instructions on running
the MDM diagnostics.
AA-FM7AA-DN

MicroVAX Diagnostic Monitor User’s Guide

AZ-GM3AA-NM

MicroVAX Maintenance Guide

2-41

RONOUS INTERFACE OPTION

2.7 DMV11-SF SYNCH
synchronous interface
The DMV 11-SF is an option for the BA200 series enclosure ONLY. The DMV 11-SF
11-SF option module
DMV
The
line.
serial
option connects the Q22-bus to a modem by using a synchronous
(Figure 2-19).
handle
bulkhead
style
(hereafter referred to as DMV11) is quad-height, with a BA200

The DMV11 serial line conforms to EIA standards RS232-C, RS423-A, and V.35.

DMV11

M8053

MKV88-1616

Figure 2-19

DMV11-SA Module (M8053-PA) with Bulkhead Handle

2-42

2.7.1
BA200 Series System Enclosures
The BA200 enclosure has a 6- or 12-slot, Q-bus backplane and one or two modular
power supplies.
Figure 2-20 shows the 12-slot BA213 and the 6-slot BA214 enclosure chassis.
The backplane implements the Q22-bus on the AB rows of each slot. The CD interconnect

is implemented in
all 12 slots. MicroVAX systems use the CD rows of slots 1 through 3, and MicroPDP-1
1 systems use
I through 4 for their high-speed memory interconnects.
BA200 series enclosures with mass storage area can hold up to four standard 13.3 ¢cm
(5.25 inch) devices
(three disk drives and one tape drive). Fixed disk drives face the rear of the enclosure, providing
easy access
to the drive signal and power cables.

BA213 ENCLOSURE

BA214 ENCLOSURE
MA-0875-87

Figure 2-20

BA220 Series Enclosure Chassis

2-43

2.7.2

Module Differences

The major difference between the BA200 series and other microsystem enclosures is the way in which you
connect external devices to the system. Option modules in the BA200 series enclosure connect directly to
external 1/0 connectors. Other enclosures require an insert panel and internal cabling between the option
module and the device.

There are two main differences between the modules used in the BA200 series enclosure and the modules
used in the other microsystem enclosures.

Option modules for external devices have bulkhead handles. These handles replace the insert

Standard Q22-bus modules (such as the RQDX3 and TQKS50) have blank bulkhead covers.

panels and internal cabling found in the BA23 and BA123 enclosures.

The module handles and blank covers form an electrical seal that complies with FCC regulations for (1)
keeping radio frequency interference generated by the system in the enclosure, and (2) keeping radio
frequencies out of the enclosure. The module handles and blank covers also help to guarantee proper airflow.
See the MicroVAX Systems Maintenance Guide (EK-001AA-MG) for further information on the BA200
series enclosure.

2.8

INSTALLATION

This section provides a step-by-step procedure for unpacking, inspecting, and installing the DMV1 1-SF

option kit. Module and system configurations are also discussed.
CAUTION

ONLY qualified service personnel should remove or
install modules.

Unpacking the Option Kit

2.8.1

Look for external damage on the shipping container such as dents, holes, or crushed corners.

Do not dispose of the packing material until the module has been successfully installed and is

operational.

Put on your antistatic wrist strap.

Attach the wrist strap and antistatic mat to the BA200 series enclosure metal chassis. Use the antistatic

Use the checklist to identify the contents of the DMV 11-SF option kit (Figure 2-21). The kit should

mat for placement of the module.

include the following:

One DMV11-S logic module (M8053)

One filler panel kit (70-24505-01). The filler panel kit should include two gap filler assemblies,

One QMA DMVII Synchronous Controller User’s Guide (EK-DMVQM-UG).

and four 1/4 inch flathead machine screws

Remove the DMV11 module from the antistatic bag.

2-44

Inspect the module for shipping damage.

Report any damage to the shipper and notify the DIGITAL representative.

DMV11

M8053

GAP FILLER ASSEMBLY

agof

So—

_—

FEREOA
XL EICKAX
IX
T

seApen

(2)
DMV11-SF

D Iy

AlO S I i I i

USER

GUIDE

Y Y Y Ye—FLATHEAD SCREWS (4)

FILLER PANEL KIT
70-24505-01
MKV88-1611

Figure 2-21

2.8.2

DMVI11-SF Option Kit Contents

Inspecting the FCC and EOS Clips

NOTE
To comply with FCC regulations, bulkhead handles
are equipped with transient protection FCC and EOS
clips. These clips provide ground through the module

handle.
1.

Ensure that there is no residue or corrosion on the FCC and EOS clips
on the module handle

(Figure 2-22). If so, remove it with alcohol. Also, ensure that there is no residue and
corrosion on the
FCC and EOS clips on the gap filler assemblies.
2.

Ensure that the FCC and EOS clips on the handle are in an arched shape. When
depressed slightly,
they should return to their original shape.

If any clip is missing or broken, replace it with EOS clip (PN
(PN 12-26340-01).

2-45

12-26922-01) or FCC clip

EOS

CLIP

FCC

CLIPS

MKV88-1613

Figure 2-22

2.8.3

FCC and EOS Clips

Software Backup

It is the customer’s responsibility to perform a software backup. DIGITAL Field Service should make sure
that the customer has taken this step before it starts to configure the system.
2.8.4

Configuration

2.8.5

Checking the System Configuration

The following sections contain information on configuring the system and the DMV11-SF option.

Complete the BA200 series enclosure configuration worksheet to make sure that you do not exceed the

system’s limits for power and bus loads (Figure 2-23).

You need to gain access to the modules installed in the system backplane before configuring the system.
Refer to the system’s documentation for further information on how to gain access to the system modules.

2-46

12-SLOT ENCLOSURE
RIGHT—HALF POWER SUPPLY

2
3
4

5
6

Neghivise
>>>

00 | 00

DISK 1

TOTAL: RIGHT-HALF

POWER SUPPLY
MUST NOT EXCEED

33.0

7.0

230.0

LEFT—HALF POWER SUPPLY

(S:ng

MODULE

fv(avaETRs)

0.0

—

- |—

9
10
1

12
MASS STORAGE

DISK

DISK
DISK

0.0

TOTAL LEFT-HALF
POWER SUPPLY
MUST NOT EXCEED

33.0

7.0

230.0 *

TOTAL BUS LOADS
MUST NOT EXCEED

350

200

6-SLOT ENCLOSURE
POWER SUPPLY

SLOT

(ABCD})

MODULE

CURRENT

AMPS

12V

POWER

(WATTS)

BUS LOADS

bDC

2
3
4

TOTAL:

POWER SUPPLY

MUST NOT EXCEED

33.0

7.0

230.0 *

—

TOTAL: BUS LOADS
MUST NOT EXCEED

NOTE:

350

200

POWER SUPPLIES MAY DIFFER. CHECK YOUR,

POWER SUPPLY SPECIFICATIONS TO CONFIRM

THE MAXIMUM WATTAGE.

MA.0876-87

Figure 2-23

BA200 Series Configuration Worksheet

2-47

To check the system configuration, perform the following steps.
1.
~

On the configuration worksheet, list all the devices already installed in the system.
List all the devices you plan to install in the system.

Fill in the information for each device, using the device information listed in Table 2-10.
Add the columns. Make sure the totals are within the limits for the enclosure.
Table 2-10 Power and Bus Load Data
Current (Amps)

Factory-Installed
Option

+S5V

CXAl16-M
CXB16-M
CXY08-M
DEQNA-SA
DMV11-M
DPV11-SA
DRQ3B-SA
DRV1W-SA
DZQ11-SA
IBQO1-SA
IEQ11-SA
KA620-AA
KAG630-AA
KDJ11-BF
KDJ11-SA/SB
MRV11-D
MS630-BB
MS630-CA
MSV11-JD
MSV11-JE
MSV11-QA
RDQX3-M
TQKS50
M9060-YA
RDS53A-EA
RD54A-EA
TKSOE-EA

1.6
2.0
1.8
3.5
4.7
1.2
4.5
1.8
1.0
5.0
3.5
6.2
6.2
5.5
3.47
1.6*
1.8
3.1
3.74
4.1
2.4
2.48
2.9
5.3
0.9
1.3
1.35

(Max)

Power

+12 V

(Max)
Watts

Bus Loads
DC
AC

200 mA
0.0
300 mA
0.50
0.38
0.30
0.0
0.0
0.36
0.0
0.0
0.14
0.14
0.2
0.19
0.0
0.0
0.0
0.0
0.0
0.0
0.06
0.0
0.0
2.5
1.34
2.4

10.4
10.0
12.6
23.5
28.1
9.6
22.5
9.0
9.3
25.0
17.5
32.7
32.7
29.9
19.6
8.0*
9.0
15.5
18.7
20.5
12.0
13.1
14.5
26.5
34.5
22.6
35.6

3.0
3.0
3.2
2.2
2.0
1.0
2.0
2.0
1.4
4.6
2.0
2.7
2.7
2.6
3.0
3.0
0.0
0.0
2.7
2.7
2.0
1.9
2.8
0.0
0.0
0.0
0.0

* Value is for the unpopulated module only.

2-48

0.5
0.5
0.5
0.5
1.0
1.0
1.0
1.0
0.5
1.0
1.0
1.0
1.0
1.0
1.0
0.5
0.0
0.0
0.5
0.5
1.0
0.5
0.5
0.0
0.0
0.0
0.0

2.8.6 Guidelines for Module Placement
The following sections provide guidelines for placing the module
in the backplane.

2.8.6.1

Bus Continuity

Bus grant signals pass through each installed module through the A connectors

shows the bus grant routing. Use a bus grant continuity card (M9074) in vacant

of each slot. Figure 2-24

bus continuity.
12

«-|-——+—-——+4—-——-—t+t——F

-4

backplane slots to ensure

——J———_L__1

O
192]

W
O

O
o

MA-0617-87

Figure 2-24

Bus Grant Continuity Path

2.8.6.2 Power Supplies
The BA200 series enclosure contains one or two separate 230-watt power supplies.
®

In the 12-slot BA213 enclosure (with two power supplies installed), the right-side power
supply

powers slots 1 through 6 and the left-side power supply powers slots 7 through 12.

In the 6-slot BA214 enclosure, the power supply is located to the left of the backplane and
powers
all 6 slots.

Each power supply in the enclosure must have a minimum 5-ampere load on the
5-volt output to maintain
regulation. If a power supply does not meet the minimum load requirement, you MUST
install a load
module (M9060-YA) in an open backplane slot powered by that power supply. The
power supply enters an
error mode and shuts down the system if the minimum load requirement is not
met.
Refer to Section 2.11, “Relocating Existing Modules,” for procedures on installing

2-49

or removing modules.

2.8.6.3

DMYV11-SA Bus Priority

Table 2-11 shows the recommended module sequence.
Table 2-11 Recommended Module Order

MicroVA X

MicroPDP-11/53

MicroPDP-11/83

KA630/KA620

KDJ11-SA/-SB

MSV11-JD/-JE

CXBI16

MS630-B/-C
MRV11
DEQNA
DPV1I
DMVI1
CXA16

KDJ11-BF
MRV11
DEQNA
DPV11
DMVI11
CXA16

CXBI16

CXY08

IBQO1*

TQKS50**

TQK50**

CXYO08

IEQI1*
DZQ11
DRQ3B
DRV1W

RQDX3**
*
**

2.8.7

MSV11-QA
MRV11
DEQNA
DPV11
DMV11
CXA16

IEQI1*
DZQI11
DRQ3B
DRVIW

RQDX3**

IEQ11*
DZQI1
DRQ3B
DRVIW
RQDX3

No restrictions on position.
Not applicable in BA214 enclosure.

Finding CSR Addresses and Interrupt Vectors

Sections 2.8.7.1 through 2.8.8 contain information on finding CSR addresses and interrupt vectors.
2.8.7.1

MicroPDP-11 Systems

2.8.7.2

MicroVAX Systems

For information on how to find CSR addresses and interrupt vectors for modules in a MicroPDP-11 system,
refer to the MicroPDP-11 Systems Maintenance Guide (EK-MIC11-SG).

To find CSR addresses and interrupt vectors manually for modules in a MicroVAX system, see the
X Systems Maintenance Guide (EK-O01AA-MG).
MicroVA

You may also use the CONFIG program in the MicroVMS or the VMS SYSGEN utility to determine the
correct CSR address and interrupt vector for the modules in the system. When you type a list of the devices
in the system, CONFIG automatically provides CSR address and interrupt vector information. Table 2-12
lists the devices supported by this utility.

2-50

Table 2-12 Devices Supported by SYSGEN

Enter at DEVICE>

Device

Prompt

DMV11

CXA16

DHVI11

CXYO08

DHVI11

DEQNA

QNA

DPV11

DRV1IW

DR11W

DZQ11

DZ11

IEQI11
RQDX3

IEQI11
UDA

TQKS50

TUS81

To use the SYSGEN utility, type the following at the system command prompt:
MCR SYSGEN
Press <RETURN>. The utility responds with the prompt:

SYSGEN>
At the prompt, type:

CONFIGURE
Press <\RETURN>. The utility responds with the prompt:
DEVICE>

At this point, enter the abbreviation for each device already installed in the system and for each device that
you intend to install in the system. Table 2-12 lists the abbreviations.
Enter one abbreviation per line, then press <RETURN>. The DEVICE> prompt prompts you for another
entry. If you are installing more than one unit of a particular device, enter a comma and the number of

devices after the abbreviation. For example, DHV11,2 indicates two DHV11 modules.

After you have entered all devices, enter <CTRL Z>. The program displays the following information for
each device entered:

(SR address and vector

Name assigned to the device by the operating system
Operating system support status (yes or no).

The program uses an asterisk (*) to indicate a floating address or vector. If there is more than one unit of a
particular device, the first address refers to the first device to be installed. To exit from the SYSGEN
utility, type <EXIT> at the SYSGEN prompt and press <RETURN>.

2-51

2.8.8

Configuring the DMV11-SF Option

Before installing the DMV 11 module, you must define two parameters by selecting them with the module’s
switches ES3 and ES4. (Figure 2-25). The parameters are listed below.
®
e

Module address (CSR)
Interrupt vector address

Select the CSR address and interrupt vector for the DMV11 by using switches on the module. The module
uses a floating CSR address and interrupt vector.

— ] j_y

LLTHIH

[E113[E101|L

)
M8053

E54
ES3

]

g
MKV88-1612

Figure 2-25

M&8053-PA Module Layout

The DMVI11 CSR address resides in the floating address space and the interrupt vector resides in the
floating vector space of the LSI bus addresses. The ranking assignment of the DMV 11 for bus address is 24
and for vector address is 46. (See Appendix B to determine the correct bus and vector address.) Configure
the correct device address using switchpack settings from Tables 2-4 and 2-5.
NOTE
The actual DMV11 settings depend on the other

modules installed in the system.

2-52

2.9

OPERATING SYSTEM SOFTWARE SHUTDOWN

It is the customer’s responsibility to shut down the operating system software.
DIGITAL Field Service personnel should make sure that the customer has taken this step before testing the

system (Section 2.10).
2.10

TESTING THE SYSTEM

Test the existing system to make sure it is running correctly.
1.

Insert the diagnostic tape cartridge into the tape drive.

Run the MicroVAX diagnostic monitor (MDM) for MicroVAX systems, or run the XXDPdiagnostic for MicroPDP-11 systems. See Section 2.6 (DMV11 System Testing) for further
information on testing and troubleshooting.

CAUTION
ALWAYS remove the tape cartridge from the tape

drive before turning the power switch off.
After successful completion of the test, remove the tape cartridge, turn the power switch off, and unplug the
ac power cord from the wall outlet.
2.11

RELOCATING EXISTING MODULES
CAUTION
Only qualified service personnel should remove or
install modules.

Check the recommended module order listed in Section 2.8.6.3. You may need to relocate existing
modules before installing the DMV11 option. If you do not need to relocate existing modules, proceed
to Section 2.11.1.

2.11.1

Modules with Handles

Use the following procedure to remove modules with handles.

CAUTION
Wear a grounded antistatic wrist strap before removing or installing modules.
1.

Note the orientation of external cables connected to the module. Carefully label and disconnect

the cables.
2.

Release the two 1/4-turn captive screws that hold the module’s handle to the card cage

(Figure 2-26).
3.

Unlock the release levers by simultaneously pulling up on the top lever and pulling down on the

bottom lever (Figure 2-27).
4.

Pull out on the module’s handle and remove it from the card cage.

2-53

Confirm the module CSR address and interrupt vector; change jumpers and switch settings,
if necessary.

Reverse this procedure to install modules with handles. Do not fasten the 1/4-turn screws until
you instaii the DMV1i modulie.

[TO RELEASE: PUSH IN, TURN

COUNTER CLOCKWISE 1/4- TURN.
TO FASTEN: PUSH IN, TURN

CLOCKWISE 1/4 - TURN.

Figure 2-26

Releasing the Captive Screws

2-54

Figure 2-27

Unlocking the Release Levers

2-55

2.11.2 Modules with Blank Covers
Use the following procedure to remove modules with blank covers.
CAUTION

Wear a grounded antistatic wrist strap before removing or installing modules.

Release the two 1/4-turn captive screws that hold the blank cover to the card cage (Figure 2-28).
Pull the blank cover away from the card cage.

Note the orientation of any internal cables connected to the module. Some connectors are not
keyed. Carefully label and disconnect the internal cables.

Unlock the module release lever by simultaneously pulling up on the top lever and pulling down on
the bottom lever. For modules with plastic handles, pull the plastic handle and remove the module
from the card cage.

Confirm the module’s CSR address and interrupt vector; change jumpers and switch settings,
if necessary.

Reverse this procedure to install modules with blank covers. Do not fasten the 1/4-turn screws
until you install the DMV11 module.
VERIFYING THE GROUND CONNECTIONS

2.12

When installing a module with a blank bulkhead cover next to a module with a recessed handle, you MUST
install a gap filler assembly between the modules to meet FCC regulations. Without the gap filler assembly,
circuitry on the module is exposed. Two gap filler assemblies (PN 70-24071-01) are provided as part of the
filler panel Kkit.

Before installing the DMV11 option module, verify the ground connections as follows.
1.

Check if any recessed-handle module has a module with a blank bulkhead cover or a flush handle
in the slot immediately before or after it.

If so, verify that a gap filler assembly is installed on the side of the blank bulkhead cover or the
flush handle that is next to the recessed-handle module (Figure 2-29).
NOTE
There SHOULD NOT be any open spaces between
the modules.

2-56

TO RELEASE: PUSH IN, TURN
COUNTERCLOCKWISE 1/4 - TURN.

;
‘

TO FASTEN: PUSH IN, TURN

CLOCKWISE 1/4 - TURN.

SN
—

NOTE:
THIS ILLUSTRATION SHOWS HOW TO RELEASE
CAPTIVE SCREWS ON ALL BLANK COVERS AND

BULKHEAD HANDLES.

Figure 2-28

Removing the Blank Cover

2-57

GAP FILLER

SCREWS =

BLANK COVER
NOTE:

THE GAP FILLER IS MOUNTED

ONTO THE BLANK COVER TO
CLOSE THE OPEN SPACE BETWEEN
THE RECESSED MODULE AND THE
BLANK COVER.

o
7

fififlfi[ |

JDDDU

_—

=
OPEN SPACE

RECESSED MODULE

MA-0610-87

Figure 2-29

Ground Connections

2-58

Install the gap filler assembly (if needed) as follows.
Using the two screws and a gap filler assembly supplied with the filler panel kit (PN 70-

24505-01), attach the gap filler assembly to the top and bottom of the side of the blank
bulkhead cover or the flush handle that fits next to the recessed-handle module. Make sure

the gap filler assembly fits into the tab indentations on the blank bulkhead cover or the flush
handle (Figure 2-30).

Ca)>

EOS CLIP

MO
—

EMI %
A

CLIPS

72 7

CLIPS \EL\

GAP FILLER

ASSEMBLY

1/4 INCH

SCREW \ ///EOS CLIP

:
\

\é/,)

N/‘

GAP FILLER ASSEMBLY

MOUNTED ON BLANK

BULKHEAD COVER

MA-0589-87

Figure 2-30

Attaching the Gap Filler Assembly

NOTE
The gap filler assemblies that are included with the

filler panel kit are provided as spares if not used with
this installation.

Place the blank bulkhead cover with the gap filler assembly onto the card cage.

2-59

2.13

Insert the flush-handle module with the gap filler assembly attached into the card slot.

Ensure that there is correct ground, with no open spaces between the two modules.

Do not fasten the 1/4-turn captive screws until you have instailed the DMV 11 module.
AVYA
]

INSTALLING THE DMV11 MODULE
CAUTION
BE CAREFUL not to snag the module’s components
on the card guides or adjacent modules.

Insert the DMV11 module into the appropriate card slot (Figure 2-31). The module will not be
locked in place.

Holding both the top and bottom release levers, lock the module in place by simultaneously
pushing down on the top lever and pulling up on the bottom lever.

Make sure that bus grant continuity is maintained from the CPU to the last module in the
backplane. Insert bus grant cards where needed.

Fasten the two 1/4-turn screws on the DMV11 and also on the other modules and bulkhead
covers in the system.

2.14

CONNECTING EXTERNAL DEVICES
NOTE
BE SURE to remove the tape cartridge from the tape
drive before turning the (1/0) power switch off (0).

After the testing has successfully completed, connect any external cables to the appropriate modules. See
Table 2-13 for cable information.

Turn the (1/0) power switch off (0) and unplug the ac power cord from the wall outlet.

Feed one of the appropriate cable ends (Table 2-13 and Figure 2-32) under the system and plug it
into the connector on the bulkhead handle. Tighten the screws on the connector (Figure 2-33).
NOTE
The DMV11-SF option cable is not included in the
option kit and must be ordered separately.

Attach a modem to the other end of the extension cable. See modem documentation for the
location of the connector, and for instructions on using the modem.

The installation procedure is now complete.
NOTE
It is the customer’s responsibility to bring up the
operating system software once installation is
complete.

2-60

Table 2-13 Extension Cables
Interface

Adapter Cable

Extension Cable

V.24/RS-232

BS19D-02

BC22F-10 10 ft (3.05 m)
BC22F-25 25 ft (7.62 m)
BC22F-35 35 ft (10.7 m)
BC22F-50 50 ft (15.2 m)

V.35

BC19F-02

BC19L-25 25 ft (7.62 m)
BC19L-50 50 ft (15.2 m)
BC19L-75 75 ft (22.9 m)
BC19L-AO 100 ft (30.5 m)

RS-423

BC19E-02

BC55D-10 10 ft (3.05 m)
BC55D-25 25 ft (7.62 m)
BC55D-35 35 ft (10.7 m)
BC55D-50 50 ft (15.2 m)
BC55D-75 75 ft (22.9 m)
BC55D-A0 100 ft (30.5 m)

15 WAY

50 WAY

DCE

25, 35, 37

DMV11-SA OR SF |:—\

)
-

ADAPTER

(] D—=—]]
EXTENSION

CABLE

CABLE
~

CUSTOMER PROVIDED
(EXISTING)
MKV88-1608

Figure 2-32

Cable Option Attachment

2-62

Figure 2-33

DMV11-SF Cable Connections

2-63

CHAPTER 3
COMMAND AND RESPONSE STRUCTURES

3.1 INTRODUCTION
This chapter defines DMV11 command and response formats in all necessary detail,
programming sequences relevant to DMV11 operation in the network environmen

and describes all

t. The CSR command

structure and.format of input commands and output responses, as well as data

port descriptions, are

described in detail. Discussions include special programming techniques, user access
to maintenance
mode, and user interpretation of status/error reporting.
3.2 COMMAND STRUCTURE
The DMV11 command set is structured into two categories; input commands
and output responses.
Brief overviews of input commands and output responses, including command
codes and the handshaking requirements, are provided in this section.
Transfer of control and status information between the main CPU resident user
program and the
DMYV11 is accomplished through four 16-bit control and status registers (CSRs).
Input commands are
issued to the DMV11 by the user program, and output responses are issued to the
user program by the
DMVI11.

NOTE
Normally only four CSRs are used, but in the 22-bit
address mode, eight CSRs are available.

3.2.1 Control and Status Registers
Four 16-bit CSRs are used to transfer control and status information. These registers are
both byte and
word addressable. The eight bytes are assigned addresses in the floating address
space in the I/O page
as follows:
16XXXO0, 16XXX1, 16XXX2, 16XXX3, 16XXX4, 16XXX5, 16XXX6, and 16XXX7.
For discussion, these byte addresses are designated byte select 0 through 7 (BSELO
through BSEL7).
BSEL10 and BSEL11 are only used in 22-bit address mode. BSEL12 through BSEL17
are not used by
the user/DMV11-command structure and are not referred to in this document.

The four word addresses are the even numbered locations and are designated select
0, 2, 4, and 6
(SELO, SEL2, SEL4, and SEL6). The CSR addresses are assigned to the floating
address space. The
floating address ranking for the DMV11 is 24 (See Appendix B). The relationshi
p between the symbolic byte and word addresses for DMV11 CSRs, and the actual CSR layout, is
shown in Figure 3-1.
Figure 3-2 illustrates the fields in CSR bytes BSELO, BSEL2, and BSEL3 that
comprise the fixed
format portion of both user-program commands and DMV11 responses. This fixed
format portion serves to identify the command/response type, address of the tributary that the command/response
applies
to, and coordinate ownership of the CSRs between the DMV11 and the user
program. Detailed bit
descriptions of SELO and BSEL?2 are provided in Tables 3-1 and 3-2 respectively.
The four bytes comprising SEL4 and SEL6 contain the fields pertinent to each user-progr
am command
and DMVI11 response. Detailed descriptions of the SEL4 and SEL6 fields are presented
in Sections 3.3
through 3.4.

3-1

BSEL!

BSELO

SELO

BSEL3

BSEL2

SEL2

BSELS

BSEL4

SEL4

BSEL?

BSEL6

SEL6

BSEL1 1

BSEL10

| SEL10*

*SEL10 IS ONLY USED IN 22 BIT ADDRESS MODE
MK-2860

Figure 3-1

DMVI1 CSRs Byte and Word
Symbolic Addresses

BSEL3

‘

BSELS

'
bl

T
i
1

3
T

2
T

0
T

TRIIBUTARIY AD[?RESS l

‘

o
}
1

BSEL?7

1
T

RQl

COMMAND TYPE | BSEL2
"CODE
SELD

o
.
i

]

COMMAND/RESPONSE ~ ©
FIELDS

IEl } BSELO

RDI

COMMAND/RESPONSE
FI;ELDS &
H

1
1

IEO

RDO

2
1

]

BSEL4
SEL4

BSEL6
SEL6

0
MK-1636

*22-BIT
MODE

Figure 3-2

Fixed and Variable Formats for Commands and Responses

Table 3-1

Bits

Name

SELO Bit Functions

Description

BSELO

Interrupt
When set, this bit enables the DMV11, upon asserting RDI (bit 4
Enable In (IEI) | of BSEL2), to generate an interrupt to vector address XXO.

1-3

Reserved

Interrupt
Enable Out

When set, this bit enables the DMV11, upon asserting RDO (bit
7 of BSEL2), to generate an interrupt to vector address XX4.

(IEO)

5-6

Reserved

3-2

Table 3-1

Bits
7

SELO Bit Functions (Cont)

Name

Description

Request In

This bit is set by the user program to request access to the data

(RQI)

port. It is cleared by the user program when the data port is not
required for further issuing of commands. The user program may
leave RQI set if successive requests for the data port are pending.

BSELI
8

Maintenance

Request

When set, along with master clear (bit 14 of SEL4) this bit

causes the DMVI1 to enter the maintenance register emulation

section of the microcode.

NOTE
Detailed discussion of maintenance register emula-

tion is presented in Section 4.8.

9-10

Reserved

Diagnostic

Mode

Reserved

When set, this bit allows diagnostic programs to change
the mode
of operation of the DMV 11 using the mode definition comman
d to
override the mode switches. Additionally, when set during a
mode
definition command, this bit causes the DMV11 not to set data
terminal ready (DTR).

Invoke P/MOP | [Invoke primary MOP mode. When set to one, this bit causes
the

Boot

DMV11

at this multipoint station to request that the control sta-

tion initiate the primary MOP (maintenance operation protocol)

boot procedure. In point-to-point networks, a DMV11 having this
bit set requests the other station to initiate the primary MOP

boot procedure.

NOTE
The master clear bit (bit 14) must also be asserted
to use invoke P/MOP.

Master Clear

When set, this bit initializes the DMV11. The clock is enabled

and the RUN flip-flop is set. Master clear is self-clearing.
15

Run

This bit controls running of the microprocessor. It is set by bus
initialization or master clear. When run is cleared the microprocessor halts.

BSEL2 Bit Functions

Table 3-2

Description

Bits

Name

0-2

Control/Response | These bits define the type of input command or output response as follows.

Code

Description

Bits
210

Buffer address/character count
(RCV) command or buffer disposition (RCV complete) response

0 0 0

0 0

Control command or control re-

sponse

Mode definition command or

information response

Buffer disposition (RCV unused)
response

Buffer address/character count
(XMIT) command or buffer disposition (XMIT complete) re-

0 0

sponse

Reserved

Buffer disposition (sent but not

acknowledged) response

Buffer disposition (not sent)
response

22-Bit Mode

This bit when set indicates to the DMV11 that the buffer address is in

Ready In
(RDI)

RDI is the DMV11 response to RQI, indicating to the user program
that it has control of the CSRs to issue a command. It is cleared by the

the 22-bit format.

user program when the data port contains the input command. Clearing
RDI returns control back to the DMVI1.

5-6

Reserved

Ready Out
(RDO)

RDO is asserted by the DMVI1 to indicate that the data ports (SEL4
and SEL6) contain an output response for the user program. The user
program must clear RDO after it has read this information. Clearing
RDO returns the CSRs to the DMV11.

3-4

3.2.2 Input Commands Overview
In general, input commands provide the means for the user program to assign,
receive, or transmit buffers to the DMVI11. Detailed field descriptions and formats of each
input command are provided in
Section 3.3
There are four types of input commands that can be issued to the

DMV11 for execution.

Microprocessor control/maintenance command;
Mode definition;
Control;
Buffer address/character count.

With the exception of the microprocessor control/maintenance
command, input commands require an
identification code in the first three bits of BSEL?2 (see Figure
3-2). These codes, which define each

command and variations of specific commands within the comman
d set, are defined in Table 3-2 and
listed in Table 3-3.

NOTE
CSR addresses are expressed in octal.

Table 3-3

Input Command Codes

Input Command Type

Binary Code(BSEL2)

Bit

Mode definition

Control

Buffer address/character count
(receive)

Buffer address/character count
(transmit)

3.2.3 Output Responses Overview
Output responses provide a means for the DMV11 to report various
normal and abnormal (error) conditions concerning the data transfer operation. Three basic response
s are provided:
e

Buffer disposition;
Control;

Information.

The buffer disposition response is used to return both used and

unused buffers to the user program.

The control response is used to report error conditions concerni
ng the microcontroller/line unit hardware, data link, physical link, or remote station. It also passes
protocol information to the user.

The information response provides information requested by a control
gram.

3-5

command from the user pro-

3.3

DMV11 INPUT COMMANDS

This section provides detailed descriptions of each input command. Command formats and data port
usages are illustrated and defined. User-program execution requirements, command variables, and action taken by the DMV11 in response to commands are discussed.
3.3.1

Microprocessor Control/Maintenance Command

This single byte command has two functions; to initialize and cause the DMV11 to start running, and to
cause entry into the microcode maintenance loop when the maintenance request bit is set. At start-up

time under normal operating conditions, this is the first command issued by the user program in order
to initialize the DMV11.

The format for the DMV11 initialization register (BSEL1) is shown in Figure 3-3. To set the master
clear bit and thereby cause entry into the DMV11 running mode, the user program moves a byte with
an octal value of 100 to BSEL1. As a result, all condition-sensitive logic in the DMV11 is reset for startup, and the start-up diagnostic is executed. When the diagnostic completes satisfactorily, the run bit in
BSELI is set to one. This indicates that the DMV11 is running and the microcode is executing.
Figure 3-4 presents a flow chart describing how to initialize the DMV11. A timeout counter is set to
avoid the possibility of the user program being caught in an endless loop in case the internal diagnostic
does not complete successfully.

5
6
|MST
BSEL1}] RUN CLR 00
7

3
DIAG
MODE

0
MNT
REQ
MK-2513

Figure 3-3

Microprocessor Control/Maintenance
Command Format

Mode Definition Command

3.3.2

Functionally, the mode definition command is used to establish the hierarchy of a network and the
characteristics of the communications line serving that network. As shown in Figure 3-5, the mode definition command contains two fields; the command type code field in BSEL2, and the mode field in
BSEL6. The mode field contains a code defining the function to be performed by the command.
With the mode definition command, the user program can designate the DMV11 as a control station, a
tributary in a multipoint network, or as a node in a point-to-point network. In addition, the characteristics (half-duplex or full-duplex) of the physical communications line connecting the network can be
defined.

The actual mode field codes and the functions implemented by each code are listed in Table 3-4.
Under normal operating conditions, the mode definition command is issued by the user program at
start-up time (after the internal microdiagnostics have executed successfully and the run bit is set).
Network discipline requires that each DMV11 in a network issue a mode definition command that is
appropriate to the network. For example, in a half-duplex multipoint network comprised solely of
DMVlls:

The user program at the control station issues a mode definition command with the mode

The user program at each tributary station issues 4« mode definition command with the mode

field set at four.
fieid set to six.

SET MASTER

CLEAR BIT
IN BSEL1

(BSEL= 1004

SET
TIME OUT

COUNTER
TO

> 0.5 SEC

RUN

BIT SET?
(BSEL1 =2OO8 )

DIAGNOSTIC

ERROR, EXIT

TO ERROR
CONTINGENCY

EXIT

EXIT TO

COMPLETE

START UP

MK-1638

Figure 3-4

Initialization of the DMV11

3-7

This network discipline also applies to DMV1ls operating in point-to-point networks with other
DMVl1is, DMP11s, DMClls, and DMRI11s.

When tributary addresses are software assigned, the mode definition command must be used at the
controi and tributary stations to configure the network and assign line characteristics.

The functions performed by the mode definition command can also be implemented by the mode selection switches on the DMV 11 module. The switches must be used to establish mode definition functions
when tributary addresses are switch assigned. The switch setting for performing the mode definition
functions corresponds to the BSEL6 codes listed in Table 3-4.

Once the type of station is set, it can only be changed by a master clear or a physical change in the
switches. If the type of station is switch assigned, a master clear has no affect. However, the switches
are overridden when the diagnostic mode bit (bit 3 of BSEL1) is set and a mode definition command is
issued.

;

BSEL3

ssesl
BSEL?

)

TRIBUTARY ADDRESS

jlr

RDO

.
3

IEl | BSELO
0

BSELZ

CMD TYPE CODE |gg 1o

BSEL4

i
6

RDI

IEO

SEL4

MODE FIELD | BSELS
2

]

SELG

MK-1639

Figure 3-5

Mode Definition Command Format

Table 3-4

BSELS6 Bit
Positions
2

0O
0O
0O
o
1
1
1
1

0
0
1
1
0
0
1
1

O
1
O
1
O
1
0
1

Mode Field Codes and Functions

Line
Characteristics

Network
Configuration

DMC11-Line
Compatibility?

Half-duplex
Full-duplex
Half-duplex
Full-duplex
Half-duplex
Full-duplex
Half-duplex
Full-duplex

Point-to-point
Point-to-point
Point-to-point
Point-to-point
Control station
Control station
Tributary station
Tributary station

Yes
Yes
No
No
N/A
N/A
N/A
N/A

3-8

3.3.3 Control Command
This command is the primary means of controlling the operation
of DMV11-implemented networks.
The format of the control command is illustrated in Figure
3-6.
At start-up time, the user program at the DMV11 control station
must issue one control command (establish tributary) for each tributary address supported in the multipoin
t network. This must be done
after issuing the microprocessor control and mode definition
commands. This causes the microcode to

create a tributary status slot (TSS) in the DMV11 data
memory for each tributary in the network.

Similarly, the user program at each tributary must issue a control
command (establish tributary) for
each tributary to be established at that station. This causes a
TSS to be created at that station for each
tributary it establishes.
In point-to-point networks, a control command (establish tributary
) must be issued at both stations. The
tributary address field in this case must be a one. This results
in the creation of a single TSS structure
at each station.
The DMV11 microcode at the control station and at all tributar
y stations uses these TSS structures to
coordinate protocol operation over the network between the
control/tributary pair. User programs, at
the control station and at the established tributaries, access these
structures to obtain operational information such as:
®

The number of messages transmitted and received:
The number of selection intervals and timeouts;

®
®

The number of reply timeouts; and

The number of various types of errors.

T
7

BSEL3

Ral

P
.
13

BSEL7

|
14

READ/

}13

|
10

9
DISABLE

POLLING

COMMON

IEl

=D/
|fss

READ
|Tss

|sg|2

]

BSEL?2

CMD TYPE CODE

SEL4

REQUEST KEY OR
TSS ADDRESS

|BSELO

BSEL6
SEL6
)

BUFFER

UNLATCH
POLLING

WRI
TSS
8

LATCH
STATE

DATA

.
15

RDI

DATA

‘

RDO

1
T

IEO

TRIBUTARY ADDRESS

BSELS

2
1

POOL
ENABLE

STATE

COMMON
BUFFER

POOL

MK-1840

Figure 3-6

Control Command Format

3-9

At the start-up of tributary stations having multiple software assigned tributary addresses, the user program at each station issues as many control commands as there are established tributaries at that node.
However, in networks where tributary addresses are switch assigned, only one control command specifying the switch assigned address is required as part of the start-up sequence. Any other nonzero tributary address in a control command is overridden by the switches.

The control command is also used by the user program at the control station to specify a unique set of
polling parameters for each tributary in the network.

During normal operation, the control station microcode can determine the polling level of any tributary
in the network and adjust the polling frequency of that tributary as necessary (see Section 5.2).

The control command permits the user program to perform a number of control functions using the
same command format. In general, each function implemented by this command requires issuing of a
single appropriately formatted control command. SEL6 is used to define the various functions of the
control command (see Figure 3-6). Table 3-5 provides a detailed description of each bit or field.
Table 3-5§

SEL6 Control Command Functions

Bit | Name

Description

0-4 | Request Key

These five bits are encoded requests from the user program. When this field is

used, bits 5 through 7 must be cleared. Request keys are encoded as shown in

Table 3-6.

|Read TSS/GSS | A control command with this bit set, allows the user program to read two consecutive locations (two bytes) of a tributary status slot (TSS) or global status
slot (GSS) without modifying it.

The TSS to be read is specified in BSEL3 and the location within the TSS is
specified in bits 0-4 of BSEL6. Notice that bit 5 is also set to indicate a read
GSS. To read a GSS location, BSEL3 is zero.

When the DMV11 receives a control command to read a TSS or GSS location,
it passes the requested information to the user program through an information
response (see Section 3.4.3). However, the requested information is placed on
an internal queue before it is passed to the user program. As a result, the information requested may change before the user gets it. This is particularly true
for number of messages transmitted/received and selection intervals.

|Read and

A control command with this bit set, allows the user program to read and clear

Clear TSS/GSS | specific locations in a TSS or GSS.

The TSS to be read is specified in BSEL3 and the location within the TSS is
specified in bits 0-4 of BSEL6. Notice that a read and clear command bit 6 of
BSELSG is also set. This gives a base octal value of 100 to which the specific
TSS address is added. To read and clear a GSS location, BSEL3 is zero.
Only the error counter sections of the TSS (7-17 octal) and GSS (15-17 octal)
can be accessed with a read and clear command.

3-10

Table 3-5

Bit | Name

SEL6 Control Command Functions (Cont)

Description

Accessing any other locations results in a procedural error.

Valid octal values for BSEL6 for the read and clear function are listed below:

Octal Value

TSS Location

107

Data messages transmitted
Data messages received

110
111
112
113
114

115

116
117

Selection intervals
Data errors outbound
Data errors inbound
Local buffer errors
Remote buffer errors

Selection timeouts
Local and remote reply timeouts

Octal Value

GSS Location

115

Remote station errors

116
117

Local station errors
Global header blockcheck and

maintenance data blockcheck
errors

These errors are covered in
detail Section 5.3.

When the DMV11 receives a control command to read and clear a
TSS or GSS
location, it passes the requested information to the user program through
an information response, and then clears the location.
As in the case of the read TSS/GSS, the information is placed on an
internal
queue and is subject to change before the user gets it. However, by reading
and
clearing, the user can keep a cumulative total.

Write TSS

A control command with this bit set, enables the user program to
write into specific locations in an associated TSS or GSS.

The TSS to be written into is specified in BSEL3 and the specific location

within the TSS or GSS is specified in bits 0-4 of BSEL6. To write to a GSS
location, BSEL3 is zero.
Notice that bit 7 of BSELS6 is also set to indicate a write TSS. This gives
a base
octal value of 200 to which the specific TSS address is added.

3-11

Table 3-5

Bit

Name

SELG6 Control Command Functions (Cont)

Description

The data to be written is contained in BSEL4 and BSELS. There are eight TSS
and five GSS parameters that can be written:

BSEL6

TSS PARAMETER
1.
2.

Transmit delay timer (XDT)
Initial polling urgency (Q) and

polling rate (R) for active

state
3.

6.
7.

230

231

Initial polling urgency (Q) and

polling rate (R) for inactive

state

232

Initial polling urgency (Q) and
polling rate (R) for unresponsive
state

233

No data message count (non-inact)

and unresponsive timeout count

(TO-UNRESP)

234

Dead timeout count (TO-DEAD)
and maximum message count (MMC)

235

Selection interval timing

counter

236

Babbling tributary counter

237

See Table 4-2 for details

BSEL6

GSS PARAMETER
l.

3.
4.

Number of sync-characters to

precede nonabutting messages
Preset value for streaming

tributary time counter

Polling algorithm update

interval (DELTA T)

Polling rate for dead tribu-

taries (DEAD T)

Fixed polling delay (poll

delay)

See Table 4-3 for details
NOTE

Some parameters are 8-bits in length. Thus, in these
cases two parameters are indicated. All user accesses are on two byte boundaries.

3-12

233

234

235
236

237

Table 3-5

Bit | Name
8

Enable

Common

Pool

SEL6 Control Command Functions (Cont)

Description
A control command with this bit set allows a specified tributary (BSEL3) to use

the common receive buffer pool. Usage of the common pool is based on a com-

mon pool quota. This quota is determined for the specified tributary by adding

the octal value in BSEL4 to the current quota. If this results in a value equal to
or greater than 377 octal, a procedural error results and the quota is reset to

376. However, a tributary may be set up for unlimited use of the common pool
by setting BSEL4 t0 377. Each time a tributary uses a commen poo! buffer, the
quota is decremented by one. When the quota reaches zero, the tributary is prevented from using the common pool. See Section 3.3.4 for more details on common buffer pool.

The common pool is checked first. If no buffers are available or the quota is
zero, or the buffer is too small, the private receive buffers are checked.

Disable

A control command with this bit set, disables the use of the common receive

Common Pool | buffer pool for the tributary specified in BSEL3.

The quota previously established for this tributary is cleared to zero.

1011 | Reserved
12 | Unlatch Poll-

ing State

Latch Polling State

| A control command with this bit set, causes the polling state level of the tributa-

ry addressed by BSEL3 to go to the active polling state. Control of the polling
activity for the specified tributary is then returned to the polling algorithm.

A control command with this bit set, establishes the polling state of the tributa-

ry addressed by BSEL3. The polling state is determined by bits 0 and 1 of
BSEL4. These bits are encoded as follow:
Bits

00
01
10
11

1&0

Polling State

Active
Inactive
Unresponsible
Dead

3-13

Table 3-6

Request Key Field Definitions (Control Command)

Octal

Code

Namie

No Request

Description

This code allows the issuing of a null control command for the purposc

of returning control of the CSRs to the DMV11. The no request code
is used when RDI is set but there is no command to issuc (see Section
4.2.3). This is effectively an NOP command.
NOTE
The
enable/disable
common
pool
and/or
latch/unlatch polling state bits in BSEL7 can be
used in conjunction with this request key.

Establish
Tributary

This control function initiates the creation of the tributary status slot
(TSS) data structure. This must be accomplished before any command is issued that uses a tributary address.

The user program at the control station must issue one estabhish tributary control command for each tributary supported in the network.
The tributary address is designated in BSEL3.

NOTE
In a point-to-point network, this control command,
with a tributary address of one in BSEL3, should be
issued at each station to establish the required TSS.

The DMV11 has 12 available TSS blocks. Each block has 64 — 8-bit
locations for storing status and other information necessary for maintaining communications over the data link.

As a result of establishing one or more tributary addresses, the
DMVI11 creates a global status slot (GSS). This GSS is part of the
overall status structure at each station.
NOTE
This control command function can also be used
during normal operation of a multipoint network to
reestablish previously deleted tributaries. In such
cases, the tributary address must be reestablished at
both the control station and the pertinent tributary
station.

NOTE

The enable/disable common pool and/or the
latch/unlatch polling state bits in BSEL7 can be
combined with this control function in a single control command.

3-14

Table 3-6

Octal
Code
02

Request Key Field Definitions (Control Command) (Cont)

Name

Description

Delete

This control function removes a specified tributary from operational
status by eliminating its associated TSS. Prior to issuing this com-

Tributary

mand, the user program must first halt the tributary being deleted.
[See request key 05 (request halt state)]. The TSS can only be rees-

tablished by using an establish tributary function. Only 12 addresses
may be established at any one time.
:

Request Start-up
State

This control function initializes the designated TSS and initiates the

DDCMP start-up sequence for that tributary. BSEL3 specifies the tributary address. Request start-up state must only be issued to tributaries that are in the halt state.

When the start-up sequence is completed, the DMVI11 notifies the

user program by issuing a comtrol response. When this response (run

state) is received by the user programs at the tributary and control
station, message traffic can begin between these two stations (see
Table 3-7).

NOTE
common pool and/or the
latch/unlatch polling state bits in BSEL7 can be
combined with this control function in a single control command.

The

Request Maint
State

enable/disable

This control function places the tributary designated by BSEL3 into
the DDCMP maintenance state.

A tributary placed in the maintenance state can only transmit and receive maintenance messages. Both the control station and tributary
must be in the maintenance state in order for maintenance message

traffic to occur.

The maintenance state must only be issued to tributaries that are in

the halt state.

NOTE
enable/disable common pool and/or the
latch/unlatch polling state bits in BSEL7 can be
combined with this control function in a single control command.

The

3-15

Request Key Field Definitions (Control Command) (Cont)

Table 3-6
Octal

Code

Name

Description

Request Halt

This control function places the tributary designated by BSEL3 into
the DDCMP halt state. All outstanding buffers are returned.

State

When a tributary is halted at the control station, the tributary is no
longer polled. When a tributary is halted by its own user program, it
no longer responds to polling.

The TSS for the halted tributary remains unchanged at both the control and tributary stations. The halted tributary can be restarted by
issuing a request start-up state control command.
NOTE

The halt state may also be used on a global basis to
return all common pool buffers. This is accomplished by using a tributary address of zero in
BSEL3 when issuing the request halt state.

Tributaries must not be using the common pool when
this function is issued. If the common pool is in use,
a procedural error of 136 is generated (see Table 37).

Write Modem

This control function permits the user program to write the contents of

Read Modem
Control

This control function causes the DMV11 to read the modem register
and pass this information to the user program through SEL4 by way

Control

BSEL4 into the DMV11 modem register. (See Appendix C).

of an information response. (See Appendix C.)
NOTE

Request key codes 6-17 and 22-37 are reserved.

3.3.4

Buffer Address/Character Count (BA/CC) Command

This command provides the user programs at both the control station and tributaries with the means to
assign, transmit, and receive buffers.

The format for this command is shown in Figure 3-7. Note that the command has two forms to facilitate
separate management of transmit and receive buffers. These two forms are distinguished by the type
code in BSEL2. A type code of zero is used to allocate receive buffers and a type code of four is used to
allocate transmit buffers.

The tributary address is specified by BSEL3 and the buffer address is contained in SEL4 and bits 14
and 15 of SEL6. The remaining 14 bits of SELS contain the character ¢
character count of zero is illegal.

3-16

In addition to allocating receive and transmit buffers, the buffer address/character count command
is
used to allocate common receive buffers by specifying a tributary address of zero in BSEL3.
These
buffers can only be used by tributaries authorized to do so by the enable common pool bit of a control
command.

When the user program has a message to transmit, it informs the DMV 11 of the size and address
message buffer. This is done by the buffer address/character count command on a one buffer

of the

per com-

mand basis. A tributary address of zero when assigning transmit buffers results in a procedural

error.

When the user program is receiving messages, it assigns receive buffers on a one buffer per command

basis using the buffer address/character count command. These buffers may be in the common
pool of
buffers or be private buffers. Each BA/CC command used to assign a buffer to be the common
pool
must contain a zero in BSEL3. Although this command assigns buffers to a common pool,

actual alloca-

tion 1s performed through the control command by enabling access to the common pool on a per
ry basis.

{

;

BSEL

TRIBUTARY

BSELS
sseL7]

'
.

B/A | B/A

CHARACTER COUNT

HIIGH S!X BITSI

IEl

CMD TYPE

BSEL4

SEL4

BSEL6

SEL6

CHARACTER COUNT
\ Low IBYTE

|BSEL2

LOW BYTE

|BSELO

BUFFER ADDRESS

)

IEO

. HIGH BYTE,

ADDRESS

BUFFER ADDRESS

tributa-

18 BIT ADDRESS MODE

MK-1641

Y
,

BSEL3

T R IlBUTARY/ ADDRE
D‘
SS

BSELS

)

BUFFER ADDRESS

.
BseL7|

BSEL11|

22BIT

IEl

CMD TYPE

M?DE

BUS ADDRESS

SEL2

BSEL4
SEL4

BITS

16-21

BSEL10

L LOWBYTE

|BSELO

BSEL2

QODE’E

CHARACTER COUNT

.
8

lowsyte

UNUSED

0
"

BUFFER ADDRESS

HIGH SIX BITS

RDI

1
T

IEO

HIGH BYTE

CHARACTER COUNT

RD 0

2
L

UNUSED

UNUSED
15

|sgir0
2

22 BIT ADDRESS MODE

*TYPE CODES
BUFFER ADDRESS/CHARACTER COUNT COMMAND - RECEIVE = 000
BUFFER ADDRESS/CHARACTER COUNT COMMAND - TRANSMIT = 100
MK-2512

Figure 3-7

Buffer Address/Character Count Command Format

3-17

In multipoint networks, user programs at both the control and tributary stations can handle allocation

——

of receive buffers in two ways:

The first method involves the allocation of receive buffers from a common pool of buffers.
With the common buffer pool enabled, receive buffers are assigned to the pool through the
buffer address/character count command on the basis of one buffer for each command is-

sued. Each buffer address/character count command used to assign a buffer to the common
pool must contain a zero in BSEL3. Although this command assigns buffers to a common
pool, actual allocation to a tributary is done through the control command by enabling access
to the pool and assigning quotas (see Table 3-5).

Inthe second method, the user program can directly allocate private receive buffers based on
anticipated message traffic using one buffer address/character count command for each private buffer allocated. In this context, a private buffer is defined as a receive buffer assigned
to a specific tributary for its exclusive use, and in all cases the address of that tributary must
be in BSEL3 of the assigning command.

Private buffers and buffers from a common pool can be used jointly at control and tributary stations in
a multipoint network. Under these circumstances, the advantages provided by both methods are available to the user program.

Private buffers can be set for unanticipated messages and/or abnormally large messages.

The preceding information involved standard 18-bit addressing. However, the DMV11 may also operate in 22-bit addressing mode. The DMV11 allows the software to set the 22-bit address mode of operation. The bit indicating 22-bit address mode is set by the user program as part of a command when
issuing transmit or receive buffers to the DMV11. The state of this bit is retained to indicate to the
DMV11 the number of bits in the buffer address.

3.4

DMVI11 OUTPUT RESPONSES

The DMV11 microcode has a set of three responses it can use to either reply to user-program commands or to inform the user program of error conditions. These responses are:
e
e

Buffer disposition response;
Control response;

Information response.

As with input commands, each output response is identified by a typecode in bits zero, one, and two of
BSEL2.

NOTE

In multipoint networks, each response issued contains (in BSEL3) the address of the tributary that
relates to the response. However, in point-to-point
netwaorks. equivalent responses always contain a one
in BSEL3.

3-18

3.4.1
Buffer Disposition Response
This response is used to return both used and unused buffers to the user program. Figure 3-8

shows the
format of this response and identifies the five methods of message disposition in BSEL2. BSEL?2
bits
zero, one, and two are encoded as follows:

Bit2

Bitl

Bit0

Buffer Disposition
Receive buffer complete
Receive buffer unused

Transmit buffer complete
Transmit buffer sent but not acknowledged

Transmit buffer not sent

Receive Buffer Complete — When a message is received successfully and stored in the assigned
main
memory buffer, the DMVI11 microcode notifies the user program by issuing a buffer disposition
response with a type code of 000. Data in the receive buffer is not valid until such a response is issued.
This response is issued for both common pool and private buffers.

Receive Buffer Unused - When the protocol for a specified tributary is halted, the DMV11 automatically returns all associated private receive buffers to the user program. To do this the DMV11
issues a
buffer disposition response with a type code of 011 for each outstanding buffer held
by the specified
tributary. This pertains to private buffers only.
7

1
;s

]

)

]

BSEL3

)

1 TRI?UTAR}( ADDRESS 1

BSELS

BUFFER ADDRESS
.

BseL7 | B/A|
17

HIGH BYTE,

B/A

CHARACTER COUNT

_HIGH SIXBITS

‘

{

IEO

RDO

TRIBUTARY ADDRESS

BSELS

)

(HIGH SIXBITS

'
.

SEL4

SEL6

BSEL4

)

9
8
7
6
22 BIT ADDRESS MODE

BSEL6

‘

22BIT|

RDI

IEI

cMD TYPE

BUFFER ADDRESS

UNUSED

|
.

IEO

RDO

»>|
1

CHARACTER COUNT
=

UNU,SED
14

UNUSED
1

BUFFER ADDRESS

BSEL7 |

BSELTT

LOW BYTE |

|BSELO

|BSEL?2

BSEL4
BSEL6

SELG

| LOW BYTE,

SEL10

CHARACTER COUNT =

MK-1842

BUS ADDRESS BITS 16-21
-|

|BSELO

BSEL2
SEL2

CODE*

CHARACTER COUNT

CMD TYPE

_ LOW BYTE

9
8
7
6
18 BIT ADDRESS MODE
7

IEl

BUFFER ADDRESS

RDI

)

1
{

2
1

BSEL11

* BUFFER DISPOSITION RESPONSE TYPE CODES:
1. RECEIVE BUFFER COMPLETE = 000

RECEIVE BUFFER UNUSED =011

3. TRANSMIT BUFFER COMPLETE = 100
4. TRANSMIT BUFFER SENT NOT ACK'd

=110

5. TRANSMIT BUFFER NOT SENT = 111

Figure 3-8

Buffer Disposition Response Format

3-19

MK-2515

The DMVI11 returns all common pool buffers if the user program issues a request halt state control
command with a tributary address of zero. When all common pool buffers are returned, the DMVI11
issues an information response indicating that the process is finished.

Transmit Buffer Complete - When a message is transmitted successfully, the DMV11 notifies the user
program by issuing a buffer disposition response with a type code of 100. Successful transmission
means that the receiving station has acknowledged receipt of the message.

Transmit Buffer Sent But Not Acknowledged - When the protocol for a specified tributary is halted, the
DMV11 automatically returns all transmit buffers currently being processed by that tributary to the
user program. To do this, the microcode issues a buffer disposition response with a type code of 110 for
each buffer sent but not acknowledged.

NOTE

During protocol operation, after seven unacknowledged transmissions of a message occur, the transmit threshold error is exceeded and the DMV11 issues a control response indicating this error (see
Section 3.4.2). The DMV11 continues to retransmit
the message and responsibility for terminating the
transmission belongs to the user program.

Transmit Buffer Not Sent - DMV11 maintains a queue of buffers to be transmitted for each tributary
address established in the network. When the protocol for a given tributary is halted, the DMVI1 returns all unused buffers in the associated queue to the user program. To do this, the DMVI11 issues a
buffer disposition response with a type code of 111 for each transmit buffer remaining in the queue.

The other CSRs used by the buffer disposition response are BSEL3, SEL4, and SEL6. The function of
these CSRs is as follows:

e
e

BSELS3 specifies the tributary address associated with the buffer disposition response.
SEL4 and bits 14 and 15 of SEL6 contain the 18-bit buffer address for the buffer being

completed or returned. For 22-bit address mode, bits 0-5 of BSEL6 are used with SEL4.

SEL6 (or SEL10 in 22-bit address mode), bits zero through 13, compose a 14-bit character
count allowing for a maximum buffer size of 16,383 bytes. A character count returned by a
buffer disposition response is designated in positive binary notation.

Protocol is halted for a tributary in one of three ways when:
1.

The user program issues a control command halting the tributary.

A DDCMP STRT message is received while the tributary is in the run state.

3.4.2

A DDCMP maintenance message is received, temporarily halting the protocol, while receive

buffers are being returned.

Control Response

A control response is an unsolicited response issued by the DMV11 when an error is detected or when
protocol information must be passed to the user program. The format for the control response is shown
in Figure 3-9. BSEL3 contains the tributary address or character count, SEL4 and bits 8 through 13 of
SEL6 contain the bus address for the affected buffer, and BSEL6 indicates the type of information
being passed to the user program. In 22-bit address mode, SEL6 contains buffer address bits 16-21 and
3-20

BSEL10 indicates the type of information being passed to the user program. These types of information
are indicated by an octal code and are listed in Table 3-7. Basically there are four categories of information.
1.
2.
3.
4.

System events
Protocol events
Network errors
Procedural errors
Table 3-7

OQOutput Codes (BSELG6)

Octal
Code

Category

002

Network

Receive threshold error — This error is reported to the user program when the

Error

number of consecutive receive errors equals seven. These receive error types

Information

are:

Message header blockcheck.

Message data blockcheck.

NAK in response to a DDCMP reply message.
Buffer temporarily unavailable.

Receive message overrun.

Message header format error.

When a message is too long for the
available buffer.

Each time the receive threshold error is reported, the counter is reset to zero.

004

Network
Error

Transmit threshold error — This error is reported when the number of consecutive transmit errors equals seven. These transmit errors consist of four
types and occur when:

A STRT message is transmitted but not acknowledged within the timeout
period.

A STACK message is transmitted but not acknowledged within the
timeout period.

A NAK.sreceived in response to a transmission with a reason code other
than REP response.

A data message is transmitted but a reply was not received within the
timeout period.

Each time a transmit threshold error is reported, the transmit error counter is
reset to zero, except when remaining in the DDCMP ISTRT and ASTRT
states.

006

Network
Error

Select threshold error — This error is reported when the selection interval time-

out counter for a given station has timed out seven times. The selection interval is the time allocated for a tributary to respond to a poll or for a point-topoint station to respond to a transmission.

Each time the select threshold error is reported, the selection error counter is
reset to zero.

3-21

Table 3-7

Octal
Code

Category

Output Codes (BSELG6) (Cont)

Information

NOTE
For more information on receive, transmit, or selection threshold errors, see Section 5.3.3.
010

Protocol
Event

Start message received while running — This response indicates that a
DDCMP STRT message was received from the station specified in BSEL3
while this station was in the DDCMP run state.
In normal operation, this message is used by a control station to inform a tributary that the control station has started protocol operation for that tributary.

The start message is also used to resynchronize the logical link between a control station and tributary. This might be necessary when message traffic is inhibited because of threshold errors or receive or transmit overruns.

When the DDCMP STRT message is received: 1) the DMV11 responds with
start message received while running, and 2) the protocol at the tributary halts
and all buffers are returned.
At this time the logical link may be restarted (request start-up state control
command).

012

Protocol
Event

Maintenance message received while running (or ISTRT or ASTRT) - This
response indicates that a DDCMP maintenance message was received by a
specific tributary while it was in the DDCMP run, ISTRT, or ASTRT state.
This causes the tributary to notify the user program, return all unused buffers
to the user program, and halt the protocol. The DMV11 then places the tributary in the maintenance state. The message that caused this event is lost.

014

Protocol

Maintenance message received while halted — This response indicates that a
DDCMP maintenance message was received by a specific tributary while it
was halted. This places the tributary in the maintenance state. The message
that caused this event is lost.

Event

016

Protocol
Event

Start message received while in the maintenance state — This response indicates that a DDCMP STRT message was received by a specific tributary
while it was in the maintenance state. No further action is taken by the microcode. The user program determines what action to take based on this response.

022

System
Event

Tributary polling state dead — This response informs the user program at a
control station that the specified tributary polling state has gone to the dead
state.

This response has no meaning in point-to-point networks.

3-22

Table 3-7

Output Codes (BSELG6) (Cont)

Octal
Code

Category

Information

024

Protocol

Run state — This response informs the user program at all stations that a specific tributary has entered the run state. The DMV11 microcode issues this

Event

response as a result of receiving a request start-up state control command and

having completed the DDCMP start-up sequence.

026

Network

Error

Babbling tributary — This response is issued to a user program to record the
occurrence of a babbling tributary. It is only used by half-duplex point-to-point

and multipoint control stations.

A babbling tributary is one which continues to transmit valid control messages
or message headers beyond the end of a programmable timeout (babbling tributary timeout counter).

The babbling tributary response usually indicates a malfunction at the transmitting station or too short a period for the timeout counter.
Recovery from this error condition generally requires human intervention at
the remote station.

030

Network
Error

Streaming tributary — This response is issued to a user program to indicate
that the remote station failed to release the channel at the end of the selection
interval. It is only used by half-duplex point-to-point and multipoint control

stations.

The streaming tributary timeout period is determined by the programmable
streaming tributary timeout counter. The timeout period starts at the end of
the selection interval.
This error condition generally indicates a modem malfunction at the remote
station or an inappropriate choice of the streaming tributary timeout counter.

Recovery from this error condition generally requires human intervention at
the remote station.

32-76

Reserved

100-276

Procedural
Error

Procedural errors — This response is issued by the DMV11 when the user pro-

gram violates the procedures designated for interfacing the DMVI11. In all
cases, the event that caused the procedural error is ignored by the microcode.

All procedural errors except octal codes 140, 300, and 302 are reported immediately to the user program. Those procedural errors are placed on the re-

sponse queue. Specific procedural violations are identified by the octal code in

BSELS6 as follows.

3-23

Table 3-7

Octal
Code | Category

OQOutput Codes (BSELG6) (Cont)

information

Code

Description

100

A command other than a mode definition command is issued before

the mode has been established. Control in with no request will not
return this error. Used for releasing the port.

102

Invalid type code used in a command.

104

Invalid mode change (for example, the mode of a tributary station is

106

A nonglobal command is issued to an unestablished tributary.

110

A nonglobal command is issued having a tributary address of zero.

112

Attempt to delete or place an unhalted tributary in the start or

114

Attempt to establish more than 12 tributaries.

116

Attempt to establish an already established tributary.

120

An invalid request key is used in a control command.

122

Attempt to assign a buffer for an unestablished tributary.

124

Attempt to assign a buffer for a halted tributary

126

Attempt to assign a buffer having a byte count of zero.

130

Attempt to assign a transmit buffer with a tributary address of zero.

132

Attempt to write or read and clear a reserved area of a tributary or

134

Attempt to use the reserved bits in BSEL7 of control command.

136

Attempt to return all common receive buffers while the common

140

Attempt to raise the common pool buffer quota to a value higher than

changed to point-to-point).

maintenance protocol state.

global status slot.

buffer pool is being used.

376 octal.
142-276

300

Reserved

Procedural

Buffer too small — This response informs the user program that the assigned

Error

receive buffer is not large enough for the current incoming message. Recovery
from this error condition is detailed in Section 4.6.2.2.

3-24

Table 3-7

Output Codes (BSELG6) (Cont)

Octal
Code |

Category

Information

302

Procedural

Nonexistent memory — This response is issued to the user program when the

Error

DMVI11 microcode attempts to access a CPU memory location that does not
respond. The address that caused the error is returned in BSEL4, BSELS, and

BSEL7 for this response.

This error is fatal to the station that initiated the memory access causing the

error. That station must be halted and restarted (see Section 4.6.2.1).

NOTE
With the exception of the buffer too small and nonexistent memory errors, the only control response
fields used by the DMV11 when posting a procedural error are the type code field in BSEL2, and

the output code field in BSEL6. All other fields remain as set by the user program in the command
that originally generated the procedural error.
304

System
Event

Modem disconnected — This response informs the user program that an on-tooff transition of the EIA signal data set ready (DSR) was detected. Such a
transition indicates that the modem is disconnecting from the communications
line.

Since this is a global response, the content of BSEL3 is zero.
When BSEL7=304, modem clear to send failure: (CTS) global response. Informs

user program that CTS failed to set after asserting request to send (RTS), or
CTS has gone from an ON to OFF transition while transmitting.

306

System

Event

Queue overflow — This response indicates that the free linked list is empty (see

Section 4.6.2.3).

This error typically indicates that for some reason output responses are being
called for faster than the microcode can process them.

NOTE
This is a global fatal error and the DMV11 initializes itself after attempting to return all information (response queue only).

Once this response is issued, the user program has three seconds to retrieve the
next pending response from the CSRs. Three seconds are allowed for each
pending response before the internal microdiagnostics clear the CSRs (see
Section 4.3 for restarting).
310

System
Event

Modem carrier loss — This control response code informs the user program
that the EIA signal carrier detect has gone from on to off while the DMV11
was in the process of receiving a message. Since this is a global response, the

content of BSEL3 is always zero.

3-25

BSEL3

;

| R

RDO

—

*BUS ADDRESS BITS 16-21
14

]

RD!

IEI | BSELO

[IMODE| cmD TYPE CODE

EVENT/ERROR
5

COLDE

BSEL2

—t

SEL2

SEL4

SEL6

COUNT LOW BYTE

]

*BUS ADDRESS OR CHARACTER
1

1
0

22BIT

}

COUNT HIGH BYTE

IEO

* BUS ADDRESS OR CHARACTER

BSEL7

2
1

TRIBUTARY ADDRESS

——

BSELS

s
1

2
T

BSEL4

BSEL6

18 BIT ADDRESS MODE

*ONLY APPLICABLE FOR NON-EXISTENT MEMORY
AND BUFFER TO SMALL ERRORS
MK-2510

Figure 3-9

3.4.3

Control-Out Command Format

Information Response

An information response is issued by the DMV11 microcode in reply to a request for information by the
user program. The format for this response is shown in Figure 3-10. The type code for this response is
010 binary as indicated in BSEL2. BSEL3 contains the tributary address and SEL4 contains the information requested by the user program. If the information requested is from a GSS, BSEL3 contains a
zero.

An information response contains a return key code or a TSS or GSS address in BSEL6 bits 0-4. The
return key codes are used in response to control request keys or protocol events and are encoded as
shown in Table 3-8. The TSS address is used in response to a read or read and clear TSS/GSS command in conjunction with bits 5 and 6 of BSELS6.

Information responses to read or read and clear TSS/GSS control commands, use the TSS address
field (bits 0-4 of BSELS6) to indicate the TSS or GSS location read. Bits 5 and 6 indicate whether the
response is to a read or read and clear input command.
3.5

TSS/GSS ACCESS

When a user program accesses a TSS or a GSS through a control command, the DMV11 reads the
designated location and passes the data to the user program by means of an information response.
Reading a TSS or GSS location results in two bytes of data from that location being stored in BSEL4
and BSELS of the information response, with the low-order byte in BSEL4, and the high-order byte in
BSELS. If a TSS is being read, BSEL3 in the information response contains the associated tributary
address. However, data read from a GSS is passed to the user program through an information response
having a zero in BSEL3.

As described in Table 3-5, any TSS or GSS location can be read, and specific locations can be read and
cleared. Along with the TSS/GSS address, BSEL6 in an information response also contains two singlebit fields that indicate a read or a read and clear TSS/GSS. These information response fields are
described in detail below.

TSS/GSS address

This field (BSELS6, bits zero to four) contains the octal address of the

Read TSS/GSS

When set, this bit (BSEL6, bit five) designates that BSEL4 and

TSS/GSS location from which the data in BSEL4 and BSELS is read.

BSELS contain the data requested by the read TSS/GSS control com-

p
A
l11allJ.
-

3-26

Read and clear TSS/GSS

When set, this bit (BSELS®, bit six) designates that BSEL4 and BSELS
contain the data requested by the read and clear TSS/GSS control
command. In addition to reading the requested TSS/GSS location, the
DMV11 also clears that location.

NOTE
The TSS/GSS locations accessible for writing,
reading, and reading and clearing, are listed and described in Table 3-5.

TRIBUTARY ADDRESS
}
{
—
—t

}

NOT USED
L
1
]

BSEL3

)

BSEL5

)

RQl

BSEL?

I
15

t
11

t
1
10

RDO

0
IEI | BSELO

READ/

CLR
1SS

|rss

READ

}

RETURN KEY OR

SEL4

BSEL6

SS
]TSS ADDRE
d
h
4

|BSEL2

CMD TYPE CODE | gg |2
—
BSELA

DATA

t
7

RDI

DATA

}

IEO

SEL6
1

O
MK-2391

Figure 3-10

Table 3-8

Octal
Code | Name

Information Response Format

Return Keys for Information Response

Description

Return Modem | This code indicates that BSEL4 and BSELS5 contain the requested modem
Status
status (see Appendix C).

Buffer Return
Complete

This code indicates that the process of returning all buffers is completed.
Buffers are returned to the user program under the following circumstances:

The protocol event STRT message received while running occurred.
This causes all private buffers assigned to the tributary designated by
the address in BSEL3 to be returned.

The protocol event maintenance message received while running
occurred. This causes all private buffers assigned to the tributary
designated by the address in BSEL3 to be returned.

Theuser programissued a control command containing the request key
request halt state causing all private buffers assigned to the tributary
designated by the address in BSEL3 to be returned.

The user program issued a global control command (BSEL3 = zero)
containing the request key request halt state. This causes all unused
common pool buffers to be returned.

Information responses containing the return key code for buffer return
complete always have zeros in BSEL4 and BSELS.

3-27

CHAPTER 4
PROGRAMMING TECHNIQUES

4.1
INTRODUCTION
Proper design of user programs for operation with DMV1 1-based
multipoint and point-to-point networks requires that consideration be given to a number of
programming topics. This chapter discusses
the following programming topics.

Command discipline and handshaking;
DMVI11 start-up;
Criteria for determining user-defined parameters;

Error counter access;
Error recovery procedures;

Booting a remote station.

These programming topics deal with interfacing the user program
and
DMV11 command/response structure.

DMV 11 microcode by using the

4.2 COMMAND/RESPONSE DISCIPLINE AND HANDS
HAKING
The command/response interface between a DMV11 and the
user program is accomplished through
the DMV11 CSRs that are addressed through the CPU I/0
page.

Since the DMV11 runs in a multiprocessing mode with the associat
ed CPU, the passing of commands
and responses through this interface must be highly discipli
ned to eliminate the possibility of a race
condition (the user program setting bits in the CSRs after
the microprocessor has read those bits). This
interface discipline requires that the user program follow two separate
procedures; one for issuing commands, and one for retrieving responses.
Figure 4-1 illustrates the control bits involved in CSR interface
discipline. These bits are located in the
DMVI11 CSRs BSELO and BSEL2. Examination of Figure 4-1
shows that BSELO contains two control
bits named interrupt enable in (IEI) and interrupt enable out
(IEO), bits zero and four respectively,
These bits when set, serve to enable the microprocessor to interrupt
the main CPU under two circumstances:

When the CSRs become available for the issuing of a comman
d after access is requested by
the user program for that purpose (IEI and RDI).

When the microcode has a response to be retrieved from the
CSRs by the user program (IEO
and RDO).

NOTE
Interrupt mode must be used, otherwise, receive
overruns and transmit underruns are very probable.

4-1

NOTE

It is recommended that the interrupt enable (IEI
and IEO) bits be set when interfacing with the
CSRs. It is imperative that they be set when

operating at 56K b/s because the microprocessor
is halted momentarily on every access to the
CSRs.

in the interThe procedures described below defining CSR interface discipline are based on operation
to using the
prior
program
user
rupt mode. As a consequence, the IEI and IEO bits should be set by the
CSR interface.

RaQl

IEO

IEl | BSELO

RDO

RDI

BSEL2
MK-2390

Figure 4-1

4.2.1

CSR Interface Control Bits

Command Discipline

At start-up time, before the user program can execute any command, it must initialize the DMV11.
This is accomplished by the program setting the master clear bit in BSEL1 and waiting for the DMV11
to set the run bit.

the user proOnce the DMV11 is initialized, commands may be issued. All commands are issued bystep
identifies
second
The
port.
data
the
of
use
the
requests
step
first
gram in two successive steps. The
the
notifies
and
command,
te
appropria
the
for
on
informati
port
the command type and the data
defined
further
is
port
data
each
of
content
specific
The
CSRs.
the
in
DMV11 that the command is
under each command description in Section 3.3. The handshaking procedure for input commands is as
follows (see Figure 4-2).

The user program requests the use of the data port to issue a command by setting request in
(RQI) bit 7 of BSELO. The user should also set bit 0 of BSELDO, interrupt enable in (IEI), at
the same time (using the same instruction) to allow the DMV11 to interrupt the CPU when
the data port is available. An interrupt is generated to XX0 when RDI is asserted by the
DMV11.

NOTE

The 22-bit mode is used when the software supports

22-address bit buffers. A “one” in bit 3 of BSEL2

indicates to the DMV11 that the software supports
the change in the command format required to support 22-address bits.

When the data port is available, the DMV11 informs the user by setting ready in (bit 4 of
BSEL2) and generating an interrupt to vector XXO.

On detecting RDI bit set, the user can: 1) load the appropriate information into SEL4 and
SEL6, and 2) load the input command code into bit 0-2 of BSEL2.

If a single command is to be issued, the user program clears RQI. If a series of commands
are to be issued, RQI can remain set until just prior to the loading of the last command into
the CSRs. By leaving RQI set while issuing a series of commands, the user program is assured of having access to the CSRs after the next response.
4-2

4.2.2
Retrieving Responses
The DMV11 issues responses in two steps. If RDI is not set, the data pertinent to the responses being
issued is loaded into BSEL3, SEL4, and SEL6. Once this is complete, the DMV11 sets the ready out

(RDO) bit and the command code in BSEL2. An interrupt through vector XX4 is generated if the IEO
bit is set. Generally, processing an output response involves the following steps:
o

The user program checks for RDO set. This is done by waiting for an interrupt.

To use the output interrupt capability, the user program must set the output interrupt enable

bit in BSELO immediately after it detects that the run bit has been set following master
clear.

When an RDO set condition is detected, the user program should move the contents of
SEL2, SEL4, and SEL6 into a working storage area and clear RDO in BSEL2 as soon as
possible. When RDO is cleared, the data port (SEL4 and SEL6) is released to the DMV11
for more input or output processing.

4.2.3

CSR Interface Interactions
User-program access to the CSRs is under complete control of the DMV11 microcode. Access
to the
CSRs is granted upon request when the user program has a command to issue, or when the microcode
has a response for the user program. Figure 4-2 illustrates the nature of the access window available to
the user program under interrupt control, when issuing a command, or retrieving a response. As previously indicated, the user program requests use of the CSRs for the purpose of issuing a command by
setting RQI. The DMV11 microcode makes the CSRs available for the issuing of a command, only
when it is not using them, by setting RDI and interrupting the user program through the floating vector

XXO0. As a result, the time period between the setting of RQI by the user program and the granting of

the CSRs through an interrupt is indeterminate.

When commands are being issued from a queue, and the last command has been issued with the user

program still having ownership of the CSRs (RDI is set), there is a mechanism for returning
the CSRs

to the DMV11. In such cases, the user program can issue a control command with the code for no
request in the request key field, thereby, signalling the microcode to ignore the contents of the CSRs.
In this way, the possible reading of erroneous data by the DMV11 microcode is avoided.
If the user program is to issue a single command, RQI should be cleared prior to issuing the command
to the CSRs, as indicated in Figure 4-2. However, if a series of commands are to be issued, the user
program can leave RQI set. In this circumstance, when a command is issued and RDI is cleared, the

microcode relinquishes the CSRs to the user program as soon as they become available. The time period between clearing RDO upon completing one command, and an interrupt initiating the next command, is also indeterminate.
When the DMVI11 has a response to be passed to the user program, it sets RDO then interrupts
the
main CPU through the floating vector XX4. At this point, the user program has ownership of the
CSRs
and can proceed by reading the response. Once the response is read from the CSRs, the user program
should immediately clear the RDO bit. User-program routines responsible for issuing commands
and
retrieving responses should limit the CSR access time required to load a command or retrieve
a re-

sponse.

4.3 DMYVI11 START-UP
Starting a DMV11 requires that the user program perform a series of steps to; 1) configure the DMV11
to operate within the context of the associated network, 2) establish user-defined parameters, and

initiate protocol operations at the DMV11.

USER
SETS

RQl

USER CLEARS RQl
NO FURTHER COMMANDS

TO ISSUE

*¥DMV11
SETS
RDI
(IED)

*DMV11
SETS
RDO
(IEO)

USER HAS TOTAL CONTROL OF CSRs

* USER CLEARS RDI TO
NOTIFY DMV11 THAT COMMAND
]} Las BEEN ISSUED

TO ISSUE COMMAND

USER HAS TOTAL CONTROL OF CSRs

TO RETRIEVE RESPONSE

* USER CLEARS RDO TO
NOTIFY DMV11 THAT
l RESPONSE HAS BEEN RETRIEVED
;

* DMV11 HAS OWNERSHIP OF CSRs
MK-2514

Figure 4-2

CSR Access Window

Configuration Procedure

4.3.1

The sequence to configure a DMV11 control and tributary station for network operation is formed by
the following steps:

Set the master clear bit and wait for the run bit to set. (See Section 3.3.1).

When the run bit is set, read BSEL4 and BSELSG.

If the contents of BSEL4 equals octal 33, and the contents of BSEL6 equals octal 305, the
start-up diagnostics have successfully executed and the DMV11 is running. Any other value
in BSEL6 indicates that an error condition was detected by the start-up diagnostics. The values and meanings of these diagnostic error codes are listed in Table 4-1.

If the DMV11 operational mode is software selectable, set the mode for that device by issuing the appropriate mode definition command (see Section 3.3.2). If the mode for the
DMV11 is selected by internal switches, this step can be ignored.

4.3.2

Specifying User-Defined Parameters

After a DMV11 is configured, the user parameters are specified. User-defined parameters include parameters used by the polling algorithm, and parameters specific to protocol operation. In addition,
those user parameters that are specific to the operation of tributaries, are stored in the tributary status
slot (TSS) associated with each tributary. Parameters that are pertinent to overall system operation are
stored in the global status slot (GSS) for the control or tributary station.
4-4

Table 4-1

Diagnostic Error Codes

BSELSé6

BSEL4

Description

101

N/A

Branch test has failed and the microcode is spinning in a loop.

102

N/A

6502 internal resister test has failed and the microcode is spinning

103

N/A

Load and store instructions test has failed and the microcode
is spinning in a
loop.

104

N/A

Compare instructions test has failed and the microcode is spinning

105

N/A

Increment and decrement instructions test has failed and the microcod
e is
spinning in a loop.

106

N/A

Shift and rotate instructions test has failed and the microcode is spinning
in
a loop.

107

N/A

Logic instructions test has failed and the microcode is spinning

110

N/A

Add with carry, subtract with carry, set and clear decimal
mode instructions test has failed and the microcode is spinning in a loop.

111

N/A

Stack push and pull instructions test has failed and the microcod
e is spinning in a loop.

112

N/A

Subroutine instructions test has failed and the microcode is spinning

in a loop.

loop.

in a

113

N/A

Ram scratchpad, CSR, and NPR address resisters addressing test
has failed
and the microcode is spinning in a loop.

114

N/A

Ram scratchpad, CSR, and NPR address resisters data test has
failed and
the microcode is spinning in a loop.

115

N/A

True interrupt test has failed and the microéode is spinning in

116

N/A

Ram data and addressing test has failed and the microcode is spinning
in a
loop.

117

N/A

Ram alternating data test has failed and the microcode is spinning

120

N/A

Indexed indirect addressing mode instruction test has failed and
the microcode is spinning in a loop.

121

N/A

Line unit message test has failed and the microcode is spinning in a loop.

305

The microdiagnostics have completed without errors.

4-5

a loop.

in a loop.

As described in Section 3.3.3, user parameters are specified through control commands configured to
address a TSS or a GSS. These control commands write the data contained in BSEL4 and BSELS5 into
the locations specified by bits 0-4 of BSEL6 (TSS or GSS address). In establishing polling and protocol
parameters, the user program has the option of accepting the default for a parameter or setting the
parameter to some predetermined value. Chapter 5 details the criteria to be used in determining optimum values for the various polling parameters. Criteria for determining the remaining parameters,
which generally concern the operation of the communications link, are presented in Section 4.6.
NOTE

Although the majority of user-defined parameters
are 16-bits in length, some are single byte parame-

ters. If the user program wishes to change one of the
single-byte parameters and accept the default for the
other, both parameters must be written. This is necessary because both TSS and GSS user-defined parameters are written on 2-byte boundaries.

The process of establishing user-defined parameters is presented as two separate steps:

Specifying user-defined parameters for control and tributary station TSS structures.

Specifying user-defined parameters for control and tributary station GSS structures.

4.3.2.1

Specifying TSS Parameters — TSS parameters that can be specified by the user program are

listed in Table 4-2 by name, BSEL3 address, size, and default value. A functional summary of each
parameter is also given. The actual order of setting TSS parameters through appropriately configured
control commands is arbitrary. The complete command series to specify these parameters for TSS
structures at a multipoint control station is listed below:

Issue a series of control commands to set the value for the transmit delay timer. This is re-

ferred to as the preset value.

Issue a series of control commands to establish the polling parameters Q and R for the three

polling levels.

Issue a series of control commands to specify values for the active, inactive, unresponsive,

and dead polling state-change parameters.

Issue a series of control commands to specify values for the maximum transmitted message
count.

Issue a series of control commands to set the selection timers for tributaries (or issue a single

command to set the point-to-point station reply timer).

lssue a series of control commands to set the babbling tributary timers.

4-6

Table 4-2

Name

User-Defined TSS Parameters

TSS Addr
(Octal)
BSEL6

(Bits)

230

Size

Default
(Octal)

Description

XDT
PRESET

Preset value for
the transmit delay
timer. This parameter provides a

fixed delay between
transmission of data

and maintenance
messages. The de-

Q (Active)
Q (Inactive)

232

Q (Unresp)

233

231

o0
OO0 OO

fault value of 0 =
no delay.
377

The initial value of
polling urgency (U)
for the tributary:

The TSS for a tributary must be assign-

ed a Q value for
each of the three
activity levels;
active, inactive,
and unresponsive.
This parameter is
applicable only to

TSS structures at

R (Active)

231

R (Inactive)

232

R (Unresp)

233

o0
OO0 GO

the control station.

100

The rate (R) by
which the urgency

(U) is increased for
the tributary.
The TSS for the tri-

butary must be
assigned an R value
for each of the
three activity
levels; active, inactive, and unresponsive. Both the
Q and R for a given
tributary are established through a

single control command. Therefore, if

4-7

Table 4-2

Name

TSS Addr
(Octal)
BSEL6

User-Defined TSS Parameters (Cont)

Size

(Bits)

Defauit
(Octal)

Description
one parameter is to
be set to a unique

value, and the default is to be accepted for the
other, both the default value and the
unique value must be
written. This parameter is applicable
only to the TSS
structures at the
multipoint control
station.

NDM-INACT

234

TO-UNRSP

234

Number of no data
messages required to
go inactive: This is
the number of consecutive polls to be
made (without receiving a data message) before changing the activity
level of that tributary from active to
inactive. This parameter is applicable
only to the TSS
structures at the
control station.

Number of timeouts
to go unresponsive:
The number of consecutive polls of a
tributary (without
response) before
changing the activity level of that
tributary from active or inactive to
unresponsive. Both
the NDM-INACT and
TO-UNRSP counts are
established through
a single control

Table 4-2

User-Defined TSS Parameters (Cont)

TSS Addr

Name

(Octal)

BSEL6

Size
(Bits)

Default
(Octal)

Description
command. Therefore,

if one parameter is
to be set to a
unique value, and
the default is to be
accepted for the
other, both the default value and the

unique value must be
written. This parameter is applicable
only to the TSS
structures at the

multipoint control

station.

TO-DEAD

235

Number of timeouts
to go dead: The number of consecutive
polls of an unres-

ponsive tributary
(consecutive selection timeouts) before the activity

level of that tributary is changed from
unresponsive to

dead. This parameter is applicable
only to the TSS
structures at the

multipoint control
station.

MXMC

235

Maximum transmitted
message count: This

parameter is a count

of the maximum num-

ber of abutting data
messages to be
transmitted by a

station before it
deselects itself.
This count applies
to the TSS structures at both con-

trol and tributary

Table 4-2

User-Defined TSS Parameters (Cont)

TSS Addr

(Octai)
Name

BSEL6

Size

(Bits)

Defauit
(Octal)

Description

stations in multipoint networks as
well as point-to-

point stations. Both

TO-DEAD and MXMC
for a given tributary are established
through a single
control command.
Therefore, if one
parameter is to be
set to a unique
value, and the default is to be accepted for the
other, both the
default value and
the unique value
must be written. At
tributary and pointto-point stations,
the polling parameter TO-DEAD is ignored.

SEL
TIMER

236

3 (seconds)
(454 Octal)

4-10

Selection interval
timer: This timer
is started when a
message is transmitted with the
select flag set, and
halted when a valid
reply is received or
the line is resynchronized. The selection timer is used
as a reply timer for
full-duplex pointto-point networks
(see Section 4.4.1).
It is used as the
select timer at muitipoint control stations, and in halfduplex point-topoint networks. This

Table 4-2

User-Defined TSS Parameters (Cont)

TSS Addr

Name

(Octal)

Size

BSEL6

Default

(Bits)

(Octal)

Description
counter counts in 10s

of milliseconds (ms)

from 10 to 655,350 ms.
BAB

TIMER

237

6 (seconds)

(1130 Octal)

Babbling tributary
timer: This timer

is used to detect
a babbling tributary (see Section
44.2).Ina

multipoint network
this parameter is
applicable only to

the control station.
However, this parameter is applicable

to both stations in
point-to-point networks operating

half-duplex.

4.3.2.2 Specifying GSS Parameters — As previously indicated
, when one or more tributary addresses are
established at a DMV11, the DMV11’s microcode automatically
creates a GSS for that control or
tributary station. The GSS parameters that can be specified
by a user program are listed in Table 4-3 by
name, BSEL3 address, size, and default value. A functiona
l summary of each parameter is also given. If a
value is not specified for a parameter the microcode uses the default
value. Specifying a user-defined GSS
parameter requires that BSEL3 in the pertinent control
command contain zero. The control commands

necessary to specify GSS parameters for a multipoint station

are listed below:

A control command to specify the number of sync-characters
(NUM SYNC) that are to precede nonabutting transmit messages.

A control command to set the streaming tributary timer.

Three control commands to establish values for the
global polling parameters delta time
(DELTA T), dead tributary (DEAD T), and poll delay, respecti
vely.

Specific user-defined TSS and GSS parameters are common
to both control and tributary stations.
Note that control commands specifying TSS parameters
must have the address of the tributary associated with the TSS being accessed in BSEL3. Similarly,
each control command specifying a GSS parameter must have BSEL3 set to zero. Since the
prior steps have covered user-def

ined TSS and GSS

4-11

parameters (see Table 4-2 and 4-3) at the control station, the two steps listed below complete the parameter-specifying process at the tributary stations:
1.

Issue a series of control commands at each tributary station to set the maximum transmitted
message count (MXMC) for each active TSS in a tributary station TSS structure. Note that
the 8-bit value for MXMC must be placed in BSELS5 of each command (the tributary station
microcode ignores BSEL4 in these commands). The procedure for determining an optimum
value of this parameter for tributary stations is the same one used for control stations.

Issue a single control command at each tributary station to set a value for the number of

sync-characters (NUM SYNC) that are to precede nonabutted transmit messages. The procedure for determining an optimum value of this parameter for tributary stations is the same
one used for control stations.

Table 4-3
GSS Addr

Name

(Octal)

BSEL6

NUM SYNC | 233

STREAM
TRIB

234

User-Defined GSS Parameters

Size

(Bits)
16

Default

(Octal)

12 (low

Description
Number of sync-characters:

speed)
17 (high
speed)

This global value specifies the number of synccharacters that are to

6 (sec.)
(1130

Streaming tributary timer
preset: This timer is used

Octal)

precede nonabutting transmitted messages. This
parameter applies to all
stations. Low speed is
defined as less than 19.2K
b/s and high speed is 19.2K
and above b/s.

to detect a streaming tri-

butary (see Section 4.4.3)
and Table 3-7). In a multipoint network, this
parameter is applicable
only to the control station. However, in pointto-point networks, this

parameter is applicable to
both stations.

DELTAT

235

200 (ms)

(24

Octal)
:

4-12

Delta time: This is the

polling algorithm update
increment. This global
parameter, which 1s ap-

plicable only to multipoint control stations,
is used by the polling

Table 4-3

Name

GSS Addr
(Octal)
BSEL6

User-Defined GSS Parameters (Cont)

Size

Default

(Bits)

(Octal)

Description
algorithm to calculate
polling urgency (see
Section 5.2.1). The default value of 200 ms is
the minimum value for this
parameter. DELTA T is also

used as the interval for

updating the transmit
delay timer.
DEADT

236

10 (sec.)
(1750

Octal)

Dead timer: This is the
interval between polls for

dead tributaries. This

global parameter applies
only to multipoint control

stations.

POLL
DELAY

237

0 (no
delay)

This parameter provides
for a fixed delay between

polls for all tributaries
in a network. If the default is accepted, the
next poll for any tribu-

tary occurs immediately

following the current

poll.

4.3.3 Protocol Operation
At this point the DMV11 has been configured

for operation in the associated network and is
ready for
protocol operation. The steps required to initiat
e protocol operation are:
1.

Place established tributaries in the ISTRT
state by issuing one control command contai
ning
the request key. Request ISTRT state for each
tributary address.

If the DMV11 is a station in a point-to-point
network, one contro

containing the request ISTRT state reques

l command must be issued

t key with a tributary address of one in BSEL3

The DMV11 confirms that the protocol is
operational at

each tributary by issuing a control

response (one for each control command
issued) containing the protocol event code
for

DDCMP run state entered.

4.4 CRITERIA FOR DETERMINING COMM
UNICATIONS LINK PARAMETERS
User-defined TSS and GSS parameters fall
into two categories: polling parameters that
provide for
user-program

control over the dynamic activity of
the polling algorithm, and communicat
ions link pa-

4-13

rameters that provide the user program with the ability to regulate data traffic over the physical communications line. Referring to Tables 4-2 and 4-3, the communications link parameters include:
Selection interval timer,
Number of sync-characters,
Babbling tributary timer,
Maximum transmitted message count,
~ Streaming tributary timer,
Transmit delay timer.

as are values
Values for the selection interval timer and the number of sync-characters are interrelated,
ted painterrela
These
count.
message
for the babbling tributary timer and the maximum transmitted
rameters are described in Sections 4.4.1 and 4.4.2.
Setting the Selection Interval Timer

4.4.1

mode selected for
The function performed by the selection interval timer at a DMV11 depends on the
for the purpose
timer
reply
a
as
used
is
timer
this
that DMV11. In full-duplex point-to-point networks,
for the associmode
the
when
timer
interval
selection
a
of message accountability. This timer serves as
ated DMV11 is one of the following:
e
e
e

A full-duplex control station;
A half-duplex control station;
A half-duplex point-to-point station.

In this capacity, it performs the link management function and provides for message accountability.
Link management is the process of controlling the transmission and reception of data over networks
comwhere there are two or more transmitter/receiver devices actively connected to the same physical pointex
half-dupl
as
well
as
munications link. This applies to half- and full-duplex multipoint networks
to-point links. On half-duplex links, only one transmitter can be active at any time, and on full-duplex
links, only one slave transmitter can be active at a time.

A station on such links can transmit when it is selected or granted ownership of the link. Link ownership
is passed through use of the select flag in the DDCMP message header. Detecting a select flag in a
received message allows the receiving station to transmit after message reception is completed. Sending
a select flag means that the transmitting station ceases transmitting after the current message is sent.
A selection timer detects the loss of a select flag by timing the interval required to receive the longest
are
message from a station. A timer is started when a station is selected and reset when valid messages was
message
(a
station
sending
the
at
exceeded
is
interval
received from that station. When the timer
not received during the period of the timer) it is assumed that messages with the select flag were either
transmitted or received in error.

At this point, the station that originally sent the messages with the select flag set assumes ownership of

the link. This station resumes transmitting as if it had received a valid select return.

be
The values assigned to select interval timers at stations in half-duplex point-to-point networks should
stations
different at both stations to avoid possible deadlock race conditions. For both multipoint control
and half-duplex point-to-point stations, the criteria for determining the value for a select timer includes
such factors as:

Maximum message length;

Number of sync-characters;
Line speed;
Line turnaround time:
Message processing delays.

4-14

As indicated in Table 4-3, the GSS parameter number of sync-char
acters has two defaults; one for lowspeed operation (10), and one for high-speed operation (15). The
operational speed range of a DMV11 is
specified by the line unit low-speed/high-speed switch which is placed
in the appropriate position when the
DMV 11 is hardware configured (see Section 2.5). In the low-speed
position the DMV 11 can operate at line
speeds up to 19.2K b/s, and in the high-speed position the device
line speed is 19.2K and greater b/s. It is
recommended that the default for the appropriate line speed
range be taken for this parameter.

Some recommended values for a selection interval timer are given
in Table 4-4 include the following overhead factors:

in Table 4-4. The calculations shown

256 bytes of data

28 bytes of header, sync, and pad characters

Total

284 bytes

The formula used to derive the values listed in Table 4-4 1S:

8 bits per byte
X

baud rate (bits

284 bytes per message + RTS/CTS delay = Timer
value (in seconds)

per second)

NOTE
Most modems include an RTS/CTS delay-that must

be included in the calculation of the value for the selection interval timer. When operating with an exter-

nal (EIA) modem, the typical delay used is 150 ms.
The delay used when operating with the integral
modem is 100 us.

Table 4-4

Recommended Selection Interval Timer Values

Bits Per Second

Calculated Timer Value for a 256 Byte Message

4 8K

473 ms + 150 ms = 623 ms (700 ms)

9.6K

236 ms + 150 ms = 386 ms (400 ms)

56K

40.5 ms + 0.1 ms = 40.6 ms (50 ms)

The values listed in Table 4-4 represent absolute minimums. In most
cases, specific applications require
additional delay time over these values to prevent a timeout during
reception of a valid message. Requirement for additional delay time can be caused by processing delays
that occur when receiving from
a non-DMV11 device, or by line delays encountered when dealing
with satellite networks. When determining this value, keep in mind that it represents the time the system
can reasonably expend waiting for

a response from another station.

When used as a reply timer, the selection interval timer sets
the maximum waiting period between sending a message and receiving an acknowledgement before taking
error recovery actions. This timeout is
necessary to recover from outages and the distorti

the protocol from being deadlocked.

on of messages by the link. This timeout also prevents

4-15

The same criteria used to determine a value for a selection interval timer in multipoint networks, are
also used to determine a value when this timer is used as a reply timer. As shown in Table 4-2, the
default value for both cases is three seconds.

4.4.2

Setting the Babbling Tributary Timer

This user parameter is applicable to half-duplex and full-duplex multipoint network control stations. A
babbling tributary is a tributary that continues to transmit valid DDCMP messages after a programmable
timeout has expired, thereby, denying equal access to other nodes. This situation is controlled by the
babbling tributary timer which monitors the total time period a tributary continuously transmits without
relinquishing the communications line. When this period exceeds the timeout period of the babbling
tributary timer, the user program is notified through a control response. The control response contains the
code for a babbling tributary along with the identity of the offending tributary. When a babbling tributary
is detected, the control station takes no action beyond this notification.

A major consideration in determining a value for the tributary timer is the total time interval that a
given tributary requires to end a selection interval. Determining the value for this timer is similar to
that for the selection interval timer because the same range of factors are used as criteria for calculating the value. The main difference in the two determinations is that the total number of message
bytes should be used in babbling tributary timer parameter calculations rather than the number of
bytes in the longest message.

A value for the maximum transmitted message count parameter must also be considered in conjunction

with the parameter for the babbling tributary timer. The user-defined parameter to set this counter

places a limit on the number of messages that a tributary can transmit during the selection period. This
is done by forcing the select flag when the count of messages received from a tributary equals the value
of the maximum transmitted message count. This count relieves the user program from having to limit
the number of messages queued for transmission in order to avoid a babbling tributary condition.

In any case, the period established for the timeout of a babbling tributary timer should be long enough
:0 ensure that timer expiration definitely indicates an error condition. In addition, the parameter assigned to the maximum transmitted message count should also be considered when establishing the period of the babbling tributary counter.

4.4.3

Setting the Streaming Tributary Timer

A streaming tributary is a tributary station on a multipoint line (or an associated point-to-point station)
that continues to assert the carrier signal on the link after it has relinquished ownership of the link. In
normal operation, ownership of the link is returned to the control station when it receives a select flag or
the period of the selection interval timer is exceeded. A timeout of the streaming tributary timer indicates a potential jamming of the link by a defective tributary station, a defective point-to-point station, or a malfunctioning modem.

The streaming tributary is started when ownership of the link is granted to the control station by the
remote station, and stopped when the carrier is dropped by that station. When a streaming tributary is
detected, through expiration of the streaming tributary timer, the user program is notified in the same
manner as with a babbling tributary. The control station does not transmit until the carrier is dropped.

Determination of a value for the streaming tributary timer requires consideration of such factors as
settling time of the communications line and modem delays. As with determining periods for the selection interval timer and the babbling tributary timer, the period specified for this timer should be long
encugh to preclude premature expiration of the timer. For most network applications the default of one
A

second 1is sufficient.

4-16

4.5 ERROR COUNTER ACCESS
The DMV11 is equipped with a large compliment of error counters designed
error conditions. The TSS for each established tributary contains seven

to isolate a wide range of
error counters along with three

statistical counters that provide background information for error analysis.

In addition, the GSS at each
to the station. The three TSS
statistical counters are 16 bits in length, and the threshold error counters
are three bits in length. The
remaining TSS/GSS error counters are eight bits long.
station contains four error counters that tabulate errors that are global

4.5.1
Reading the Counters
Both TSS and GSS counters are accessed through an appropriate control
command with the content of
the requested counter or counters being returned through an information
response (see Sections 3.3 and
3.4). Through the control command, the user program has the option of reading,
or reading and clearing
the counters. When doing error analysis it is recommended that a user
program read and clear these

counters to assure a zero-base for subsequent sampling of the
counters. If copies of the counters are

being maintained in main CPU memory, it is also recommended that counters

be read and cleared.

NOTE

The three-bit threshold error counters are automatically reset when the maximum count is reached so
that access to these counters is restricted to reading

only.

The DMV11 error and statistical counter structure is designed to be complimen
this complimentary structure, consider the data errors inbound counter

tary. As an ex mple of
and the data messages received

counter. The data errors inbound counter tabulates the errors related
to the validity of message reception such as block-check errors, whereas, the data messages received counter
records the total number
of messages received. A ratio of message reception errors to total number
of messages received can be
derived from these two counters.

4.5.2 Counter Skew
When performing error analysis, there is a potential of skew between counts

the requirement that counters be read one at a time. The probability of

due to read time lags and
skew between counts is a func-

tion of line speed; the higher the line speed, the greater the probabili
ty of a skew condition. An example
of this potential skewing is the possible discrepancy between the number
of selection intervals and the
number of selection timeouts. A skew could result from additional selection
timeouts occurring while
the counters are being read.
:

If circumstances require that error/statistical counters be read without the potential
for skew, this can
be done by halting the protocol at the tributary. With the protocol halted,
the contents of the error/statistical counters in a TSS and in the GSS are frozen at the counts
recorded when the protocol
was halted. The counters can then be read without the problem of skew
due to read time lags.
4.6 ERROR RECOVERY PROCEDURES
Within a DMV11-based network, there are three basic levels of error recovery
involving

gram:

Procedural violations where only the user program is notified.

Recovery from errors requiring protocol shutdown initiated by the

Fatal errors resulting in system shutdown with minimal notice to the user

Referring to Table 3-7, procedural error codes from 100 to 140 are

no recovery required. The remaining two procedural errors

the user pro-

user program.
program.

reported to the user program with

(codes 300 and 302) involve error recovery

levels two and three respectively. All network errors require recovery
through protocol shutdown, and
the control response (queue overflow) could result in network shutdown
.

4-17

Recovery from Network Errors

4.6.1

In all cases, recovery from network errors requires that the protocol be halted at the tributary or station
recording the error. Two similar but separate procedures are recommended for recovery from threshold
errors, and babbling and streaming tributary errors. These recovery procedures are described below.
4.6.1.1 Recovery from Threshold Errors - DMV11 threshold errors are detailed in Section 5.3.3. The
recommended recovery procedure to be initiated by the user program at the station recording the errors
is presented below:

Halt the protocol (see Table 3-6).

Read the error counters to determine the nature and cause of the threshold error condition. If
the error results from a shortage of receive buffers, correct the condition. If the transmit or
selection threshold is being exceeded, check the operational condition of the remote station.

When the conditions causing the errors have been eliminated, restart the protocol (see Section 4.3.3).

4.6.1.2 Recovery from Babbling and Streaming Tributary Errors — Babbling or streaming tributary errors are created when their respective timers are exceeded. Therefore, a timeout can result from an
actual error condition, or because the period of the timer is too short for the type of message activity on
the line (see Sections 4.4.2 and 4.4.3). A suggested recovery procedure to be used when encountering
these conditions is:

Halt the protocol.

Check the value of timer parameters and increase if the value is not appropriate.

Restart the protocol (see Section 4.3.3).

If this error condition persists, reconfigure the station as specified by Section 4.3.1.

When the cause of the timeout originates at the remote station, action must be taken at the
remote station to ascertain and correct the fault. The local station is at fault only if the values

of the timer parameters are inappropriate.
Recovery from Procedural Errors

4.6.2

The three procedural errors that require a recovery procedure are:
1.
2.
3.

Nonexistent memory error.
Buffer too small error.
Queue overflow error.

The recovery procedure for each of these errors is detailed in Sections 4.6.2.1 through 4.6.2.3.

4.6.2.1 Recovery from a Nonexistent Memory Error — Nonexistent memory errors occur when the
DMV11 tries to access an allocated receive or transmit buffer having an invalid bus address. When this
error is detected, the DMV11 posts a control response to the user program containing the invalid address (see Section 3.4.2). It is up to the user program to determine whether the nonexistent address
concerns a transmit or receive buffer.

NOTE

Depending on microcode processing circumstances,
the nonexistent memory address returned to the user
nrogram counld have heen incremented to the next sequential location.

4-18

The suggested recovery procedure for this error is as follows:
1.

Halt the protocol for the tributary or station recording this error to initiate return of all outstanding buffers.

If the error concerns a buffer from the common pool, the user program should issue the
global halt command to initiate return of all outstanding receive buffers from the common pool.
3.

Restart the protocol and reallocate buffers as necessary.

Persistent recurrence of this error indicates a possible main CPU or DMV11 malfunction.

NOTE
If the network line speed is 56K b/s, the requests for

retransmission generated by a nonexistent memory
address can result in the overflow of the DMV11 response queue causing a fatal system error (see Sec-

tion 4.6.2.3).

4.6.2.2

Recovery from a Receive Buffer Too Small Error - When the DMV11] receives a message, it
first checks for the availability of a buffer from the common buffer pool linked list, and if one
is available, it uses that buffer. If the common buffer pool is empty or not enabled, the private buffer
linked
list is checked. If a private buffer is not available, the receiving station NAKs the incoming message.
The steps taken by the DMV11 microcode in this process are listed below.
1.

Is the message number in sequence? Yes, continue; No, ignore message.

Is the common buffer pool enabled? Yes, continue; No, go to Step 6.

Is the common buffer pool quota = 0? Yes, go to Step 6; No, continue.
Is a common pool buffer available? Yes, continue; No, go to Step 6.
Is the common pool buffer too small? Yes, go to Step 8; No, use this buffer.
Is a private buffer available? Yes, continue; No, send NAK - buffer temporarily unavailable.

Is private buffer too small? Yes, send NAK - buffer too small; No, use this buffer.
Is private buffer available? Yes go to Step 7; No, send NAK ~ buffer too small.
NOTE
The DMV11 does not scan the common pool or private linked list structures looking for a buffer of suf-

ficient size. Rather, it uses the next available buffer
from the list.

Buffer too small errors apply only to receive buffers. The procedure for recovery from this error
is
dependent on whether the allocated buffer is from the common pool or is a private buffer. The
applicable recovery procedures are explained below.
A.

Common pool buffer too small
1.

Assign a private buffer of sufficient size to the receiving tributary through a buffer address/character count command (see Section 3.3.4).

4-19

Both private and common pool buffers too small

Halt the protocol for the offending tributary to initiate return of all outstanding private buffers.

Restart the protocol.

Assign a private buffer of sufficient size to the receiving tributary through a buffer ad-

dress/character count command (see Section 3.3.4).

Private buffer too small, and common pool not enabled

If buffers from the common pool are available to other tributaries, and are of sufficient size,

enable common pool buffers for this tributary (see Section 3.3.4).

If the common buffer pool is not in use for other tributaries, follow recovery procedure B
above.

4.6.2.3 Recovery from a Queue Overflow Error — This error is always fatal to the DMV11 recording
the error since it forces automatic shutdown of the device. The basic cause of this error is the inavailability of link blocks from the free linked list (see Section 5.4.1.1). Typically, this error results
when the internal response queue overflows because the DMV11 generated responses faster than the
user program could retrieve responses from the queue. This error can also occur if an inordinate number of receive buffers have been allocated. One cause of response queue overflow is the occurrence of
repetitive nonexistent memory errors in high-speed networks (see Section 4.6.2.1).
When this error occurs, the DMV11 posts the most current entry in the response queue to the user
program. The user program then has three seconds after being interrupted to retrieve the response. If it
is retrieved during this three second window, the next response is posted. As long as the user program
retrieves each response within this window, the process continues until the internal response queue is
empty. These responses can then be analyzed to determine the cause of the queue overflow.

After the last response has been posted, or the three second response period has expired, the DMV11
shuts itself down. At this point, returning the DMV11 to operational status requires that the start-up
procedure be initiated from the beginning (see Section 4.3).

4.7

BOOTING A REMOTE STATION

DMV 11-based networks provide the user program, at the multipoint control station or point-to-point
station, with the ability to boot the main CPU at a remote station that has been shut down due to power
outage or software malfunction. There are three ways this boot function can be performed:
1.

Remote load detect: The control station starts the primary MOP boot procedure for a remote

station.

Power-on boot: The first poll received after power-up at the remote station causes the
DMV11 at that station to request that the control station start the MOP boot procedure.

Invoke primary MOP: The user program at the remote station causes the DMV11

that the control station start the primary MOP boot procedure.

4-20

to request

NOTE
Control station is either a multipoint control or
point-to-point station that is transmitting (over the
link) the boot or requested program to the remote
station. Remote station is either a multipoint tributary or point-to-point station that is receiving
(over the link) the boot or requested program.
NOTE
remote load detect, and invoke
primary MOP are not mutually exclusive. All three
features could be used in a particular application.
Power-on

boot,

Primary MOP boot procedures require that the DMV11 be switch-c
onfigured in the manner specified
in this section. The steps taking place at the remote station and
over the communications line leading to
each of the three primary MOP boot functions are presented in
the following sections.
4.7.1
Steps Leading to a Remote Load Detect Boot
The steps taking place at the DMV11 remote station and its
host CPU in response to an enter MOP
mode message from the control station are:
1.

The DMVI11 NPRs a tight-loop routine into main memory
.

The DMV11 transfers control to the routine through the power
fail/restart vector. This routine inactivates the CPU to prevent any intervention during the NPR
process.

The DMV11 then sends a primary MOP request program message
to the control station. The
control station responds in turn with a primary MOP memory
load with transfer address message containing the boot or related program to be loaded
into main memory at the remote
station.

The DMV11 NPRs that program into main memory, then
starts executin

g the program.

At this point the remote station is operating in the manner
program.

The steps occurring over the communications line during a remote

intended by the down-line loaded

load detect boot are:

The control station sends an enter MOP mode message to a

The remote station recognizes the address and password in the
message, then inactivates its
host CPU.

The remote station then responds with a primary MOP request

The control station responds to this message with a primary
MOP memory load with transfer
address message containing the boot or related program to be loaded
into the host CPU at the

remote station.

program message.

remote station.

4.7.2 Steps Leading to a Power-On Boot
When power is restored after a shutdown at a remote station,

the DMV11 performs the same steps used

during a remote load detect boot. However, the first two steps
are omitted, and the tributary station responds to the first

performed over the communications line

poll from the control station with an MOP

request program message. The same sequenc
e used in the remote load detect boot procedu
re is then

followed.

4-21

4.7.3

Steps Leading to an Invoke Primary MOP Boot

This boot operation is initiated when a user at a remote station sets the boot and master clear bits in the
DMV11 initialization register (see Section 3.3.1). The steps taken by the DMVI1 are the same as with
a power-on boot.

4.7.4

DMV11 Switch Settings for the Boot Functions

be conAt remote stations, in networks supporting the primary MOP boot functions, the switches mustTable
2and
2.5
figured in a specific way in order to properly perform the boot functions (see Section
6).

NOTE

The switch setting procedures described below apply
only to tributary stations in a multipoint network
and one node in a point-to-point network.

boot
The unit number (zero or one) of each DMV11 must be appropriately set. This number allows the
floating
host’s
the
(within
DMV11
specific
program, once it is loaded into the host CPU, to identify the
address space) performing the boot.

NOTE

When primary MOP booting is supported in a network, the operating mode of each tributary station
eligible for booting must be set in the switches rather
than through the mode definition command.

(switch
The operating mode of a DMV11 is specified by setting the mode enable switch to one (OFF)required
the
to
8
and
7,
6,
numbered
switches
setting
and
pack),
number 1 of the boot enable switch
operating mode. The settings for these switches are listed in Table 4-5.

function at a
4.7.4.1 Switch Settings for the Power-On Boot Function - To enable the power-on boot be
set to one
must
boot)
n
(power-o
pack
remote station, switch number 4 of the boot enable switch
switch
address
DDCMP
the
in
set
be
must
(OFF). In addition, the tributary address of this station
pack.

4.7.4.2 Switch Settings for the Invoke Primary MOP Boot Function - The DMV11 switch settings for

the invoke primary MOP boot function are the same as those for the power-on boot function. However,
the setting of the power-on boot switch has no affect on the invoke primary MOP boot.
An additional feature of the invoke primary MOP boot and remote load detect is that it may allow the
tributary address of the remote station to be software assigned instead of switch assigned. This feature is
only valid for remote stations that are multipoint tributaries. To use this feature, the following conditions
must exist.

The tributary address/password in the DDCMP address switch pack must be zero.

The user program at the remote station must have established the tributary using the control

command (establish tributary). If the remote station is using the multiple address tributary
option, the tributary address used for booting must be the first one established.
NOTE

Invoke primary MOP boot with the software-assigned tributary address does not work if the poweron boot switch is enabled.

4-22

Table 4-§

Mode
Switches

Mode Switch Settings

Line
Characteristics

Network
Configuration

DMC11 Line
Compatibility

Half-duplex

Point-to-point

Yes

OFF ON

Full-duplex

Point-to-point

Yes

OFF ON

Half-duplex

Point-to-point

OFF OFF ON

Full-duplex

Point-to-point

Half-duplex

Multipoint control

N/A

OFF

station

OFF ON

OFF

Full-duplex

Multipoint control
station

OFF OFF

Half-duplex

OFF OFF OFF

Full-duplex

N/A

Multipoint tributary
station

N/A

Multipoint tributary

N/A

station

4.7.4.3

Switch Settings for the Remote Load Detect Boot Function —
To enable the remote load detect
boot function at a remote tributary station, switch number
5 of the boot enable switch pack (enable

remote load detect) must be set to one (OFF). For the
remote load detect boot function, the switchspecified tributary address also serves as the password which
is contained in the enter MOP mode mes-

sage.

When using boot functions in point-to-point networks, the tributary
address/password switches can, for
security purposes, be set to a unique value since the address
of a point-to-point node is always known to

be one.

4.8
MAINTENANCE REGISTER EMULATION
The DMV11 is placed into maintenance mode when the user
program sets bits 0 and 6 at the same time
in BSEL1. When this happens, the microcode enters
a maintenance loop and sets MNT RDY (bit 7 of
BSEL?2) to indicate that the microcode is ready to receive
a command as defined by bits zero through
three of BSEL2 (see Figure 4-3). The functions of these
commands are described in Table 4-6.

NOTE
The microdiagnostics must complete tests 1-12 as a
minimum before allowing entry into the maintenance

loop.

In the maintenance mode, the functions of the CSRs are redefine

d as follows:

BSELDO, bits zero and four, enable the respective micropr

by bits one and two if an internal 6502 interrupt occurs.

4-23

ocessor LSI bus interrupts as defined

See Figure 4-3.

BSEL?2, bits zero through three, define the maintenance loop command function. Bits four and
five are used for interrupting the CPU on command complete. These interrupts are enabled by
BSELO. Bit seven is set by the microprocessor when the maintenance loop is ready to receive

another command function in bits zero through three (Table 4-6).

SEL4 contains 2 DMV11 memory location for function codes one through five (Table 4-6).

SEL6 contains data written or read for functions one, two, and six. It also contains a 16-bit
address for functions three and four.

SEL10 contains the upper address bits for functions three and four. Only the low byte of this
CSR is used.

NOTE

BSEL10 and 11 are only used in 22-bit mode.
BSEL12 through 17 are not shown because they are

never used by the user/DMV11-command structure.

BSEL

FOR FUNCTIONS 1-5

“g

INT

BSEL4
SEL4

BSEL6

DATA READ OR WRITTEN FOR FUNCTIONS 1, 2 & 6 or 16 BIT ADDRESS FOR FUNCTIONS 3 & 4
3
¥

i
T

1
L

i
T

1
M

I
¥

3
M

NOT USED

BSEL11

]

" UPPER ADDRESS BITS
FOR FUNCTS 3 & 4

i
UNUSED
7

]

SEL6

SEL10

BSEL10

]

BSELO
BSEL2
SEL2

FUNCTION CODE

FOR FUNCTIONS 1-5

~A"

DMV11 MEMORY LOCATION (LOW BYTE)

DMV11 MEMORY LOCATION (HIGH BYTE)

BSELD
BSEL7

RDY

INTB|

INTA

MNT

NON-MASKABLE INTERRUP
FLAG REGISTER FROM PIA_

BSEL3

4P | uP | EN

MNT
REQ

MTR
CLR

RUN

*MI
OCCURRED

MK-2517

Figure 4-3

DMVI11 Maintenance Loop Command Format

4-24

Table 4-6

Maintenance Command Functions BSEL2 Bits 0-3

Octal Code
Bits 0-3

Function

Reserved to avoid unpredictable results.

Read DMVI11 memory location specified by SEL4 (16-bit address specifying a
byte). SEL6 contains the data read from this location.

Write DMV11 memory location specified by SEL4. SEL6 contains the data
written to this location.

Read 256 bytes of DMV11 memory. SEL4 points to the starting DMV11 memory address from which the information is read. The lower eight bits of this ad-

dress are ignored. SEL6 and BSELS point to the starting LSI-11 bus address
where the information is stored.

Write 256 bytes of DMV11 memory. SEL4 points to the starting DMV 11 mem-

ory address to which the information is written. The lower eight bits of this address are ignored. SEL6 and BSELS point to the starting LSI-11 bus address
from which the information is read.

Set the 6502 microprocessor’s program counter to the value contained in SEL4.
This is used to start the microprocessor executing code at the DMV 1 memory
location specified by SEL4.

Set internal loop and null clock for functional diagnostics. Null clock
is initialized for 56K b/s.

Set maintenance interrupt flags and clear interrupt disable in processor status.

4-25

CHAPTER 5

ASPECTS OF DMV11
MICROCODE OPERATION

5.1
INTRODUCTION
The functionality of the DMV11 results from the microprocessor and its associated microprogram ormicrocode. This chapter discusses the microcode as it relates to:
e

The polling algorithm,

Error recording, and

The internal data base.

5.2 DMVI11 POLLING ALGORITHM
In a polling operation the tributaries are in effect asked one by one whether they have anything to
transmit. To accomplish this, the control station sends a polling message with a unique tributary address down the line. The station which recognizes the address responds with data messages or a positive
response.

With DMV11s, polling is based on a priority scheme which is derived automatically and applied dynamically by the microcode. To control polling and data message transmission, the DMV11 uses the
following information:

The tributary’s recent poll history,

The tributary’s user-defined parameters,

The tributary’s protocol state.

In regard to protocol state, the multipoint network control station polls all established tributaries that
are not in the DDCMP halt state. The protocol state of every established tributary is maintained in the

associated TSS by the control station. When a tributary is eligible for polling, all outstanding transmit
messages for that tributary are sent as the poll, up to the limit imposed by the maximum transmitted
message count. If no transmit messages are available for a tributary eligible for polling, the DMV11
automatically transmits the appropriate DDCMP control message.

The DMVI11 polling algorithm determines which tributary is to be polled next, based on each tributary’s polling urgency level. The DMV11 polling algorithm employs the user-defined TSS and GSS polling parameters as the basis for categorizing tributaries into polling levels. The polling algorithm also
determines the rate at which polling urgency is increased within each polling level. A tributary’s polling
level is based on its recent response history. This classification mechanism, combined with periodic incrementing of polling urgency, results in the most active tributaries being polled most often.

5-1

5.2.1

Calculating Polling Urgency

The polling urgency (priority) of each tributary is periodically calculated when a global timer expires.
This periodic calculation enables the algorithm to enforce minimum poll intervals for each tributary,
and to account for competition between tributaries. The minimum poll interval prevents unneeded polls
from:
e
e
e

Delaying other tributaries,
Interfering with output traffic, and
Causing unnecessary processor overhead.

The polling urgency of a tributary is calculated as a linear function of time elapsed since the last poll.
The calculation is truncated when the maximum value of 255 is reached. The three parameters in this
calculation are:

1.
2.
3.

Q - the initial value of the polling urgency (U);
R — the rate at which Q is to be increased;
DELTA T - the polling algorithm global update interval.

Figure 5-1 shows the relationship between these three parameters. The appropriate choice of Q and R
can give a variety of behaviors. For this reason, the choice of these values must be based on the desired
performance. One method of choosing Q and R is to define the minimum poll time and the time to
reach maximum poll urgency, and to use these values in the following equations.
Minimum poll time = 128-Q (DELTA T)
R

Time to reach maximum poll urgency = 255-Q (DELTA T)
R

DELTA T is the user-defined period of the global timer and its value depends on the line speed. It must
be smaller than the smallest nonzero minimum poll interval, but no smaller than 200 ms. The poll priority is calculated for each tributary and stored in a single byte of the TSS. With every DELTA T, the
polling urgency byte is updated. The following interpretation is placed on its value. These values are
represented as base lines on the graph of Figure 5-1. Figure 5-2 shows the relationship of the polling
urgency to different values of Q and R.

0-127

Do not poll the tributary. The minimum poll interval has not expired.

128

Minimum poll interval has expired. The tributary is eligible for polling.

129 — 254

Minimum poll interval is exceeded. The tributary is eligible for polling. The
higher values indicate increasing priority in the event of competition between
tributaries.

255

Maximum poll urgency is reached. Competition between tributaries at this pri-

ority is round-robin.

This method of determining values for Q and R is applicable when static behavior is desired. For many
applications, however, dynamic behavior can improve performance by polling active tributaries at a
faster rate and with a higher priority than inactive tributaries.

During each DELTA T time period, the control station polling algorithm updates the urgency of each
operational tributary by adding the value of R for the appropriate polling state (excluding dead) to the
urgency value of each tributary. This updating sequence is performed on the TSS data base in the order
xaa

5-2

in which tributaries were originally established at the control station. When the polling algorithm deter-

mines that the next poll is to be sent, it selects the tributary to be polled by scanning the TSS data base
(in the original order of tributary establishment), starting at the TSS following the last tributary polled.

In this process, the tributary having the highest value of U from active, inactive, and unresponsive
tributaries is selected as the next tributary to be polled.
TIME TO

MAXIMUM URGENCY

»dyr————————
——— — ——————
———
—
——
—
7

ELIGIBLE FOR

POLLING

i’

MINIMUM

POLLING INTERVAL

o 128 - - - - T T - - - . - .o 127

Yrr - -

———

NOT POLLED

|lll|llllll‘lll‘llllll|llIlll‘ll

Yl.lIIIj—

MK-2643

Figure 5-1

Interrelationship Between Polling Parameters Q, R, and DELTA T

If an urgency of 255 is detected during the process of scanning the TSS data base for the tributary
having the highest value of U, the scan process is halted and that tributary is immediately selected
for
polling. Once the selected tributary is polled, its urgency reverts to the assigned value of Q for
its polling level.

Dead tributaries are polled at a rate determined by the user-defined parameter DEAD T. One
dead
tributary is polled at each expiration of the DEAD T timer, and the scan of dead tributaries is
resumed
from the last dead tributary polled.

5-3

2556

|
|
|
]

I
I

|
|

)

8
4

3
9

127

5
v

2
<
-

0//*’

/}’

~] |

200ms

3.2 40

8.0

6.375
DELTA

9.55
200ms

12.0

16.0
MK-2647

Figure 5-2 Relationship Between Polling Parameters Q, R, and the Minimum Polling Interval
The dynamic polling algorithm uses Q and R values based on dynamically modified states. There are
four of these states:
1.

Active - The polling algorithm maintains a tributary as active when it responds to polls with

data messages.

Inactive — The polling state of an active tributary is changed to inactive when it responds to a
consecutive number of polls with nondata DDCMP messages. The count of consecutive nondata messages received from a tributary in the active state is designated by the user-defined
parameter NDM-INACT (number of no-data messages required to go inactive).

Unresponsive — A tributary currently active or inactive is changed to the unresponsive state
when it fails to respond in any way to a consecutive number of polls (each poll results in a
selection timeout). The count of consecutive polls without responses is designated by the
user-defined parameter TO-UNRESP (number of timeouts to go unresponsive).
Dead — A currently unresponsive tributary which continues to be unresponsive to consecutive
polls is changed to dead. This occurs when the number of selection interval timeouts designated by the user-defined parameter TO-DEAD (number of timeouts to go dead) is exceeded. Unlike tributaries in the other polling states, dead tributaries are always polled on a
..... d_eahin

h
ith the period between polls being
lUUllU'rOUin UaS'lS Wit i€ POriOu DOLWISln punis Yot

parameter DEAD T (dead timer).

determined by the user-defined global

When specifying the parameters controlling polling levels, the user has the option of accepting the

defaults (see Table 4-2 and 4-3), or selecting specific values in place of these defaults. The user pro-

gram can set the polling state of a tributary to any state at any time by issuing a latch polling state
control command. The polling state imposed by a control command remains in effect, irrespective of

tributary performance, until polling control is handed back to the polling algorithm by the user program. This is done by issuing an unlatch polling state control command.
Figure 5-3 shows the relationship of the the default values of Q and R for the active, inactive, and
unresponsive polling states.

255

T
ACTIVE Q=2565,

R=0

ELIGIBLE FOR

POLLING

&,
0//0
)
>
O
Z
w

S128}p¢o——

b v o i o

L A

o]
g

NOT POLLED

0i
200ms

|
1.2sec

2.60sec

DELTA T =200ms
MK-2642

Figure 5-3

Relationship Between the Default Values for Q and R for the Three
Polling Activity Levels

5-5

Each tributary has Q and R values defined by the user for the active, inactive, and unresponsive polling
states. This allows dynamic modification of the behavior of the polling algorithm. The basic mechanics
of the polling algorithm are:

If a tributary always responds to a poll with data. it remains in the active state. The polling
urgency in this case is calculated using the Q and R values specified for the active state.

If a tributary responds to a user-defined number of consecutive polls with no data messages
(ACKs only), polling is changed to inactive. The polling urgency is then calculated based on
the Q and R values defined for the inactive state.

If a tributary in either the active or inactive states fails to respond (times out) to a predetermined number of consecutive polls, the polling state is changed to unresponsive. The Q
and R values defined for the unresponsive state are used to calculate the polling urgency.

If a tributary in the unresponsive state fails to respond to a predetermined number of consecutive polls, the polling state is changed to dead. The user is notified of this transition by a
control response. Polling dead tributaries is very time-consuming because it usually requires
a timeout. Therefore, dead tributaries are not polled on a priority basis. Instead, a global poll
interval is defined for dead tributaries. Each time this timer expires, a single dead tributary
is polled. If at any time a dead tributary responds to a poll with a data message or ACK, its
state is changed to active.

NOTE

A tributary (not in the active polling state) is automatically returned to the active state when it responds to a poll with a valid data message. It also
becomes active when the user program allocates a
transmit buffer to it.

Figure 5-4 is a state diagram describing the transitions between polling states. The actual transitions are

dependent on the particular polling parameters.

The user may control sending of all polls by defining a poll delay interval that must expire before a poll
can be sent.

The program-selectable parameters which pertain to polling are included in Table 4-2. These parameters are set by the user with a write TSS command.

5.2.2

Criteria for Determining Polling Parameters

Although there are no absolute rules for determining polling parameters, there are general guidelines
for deriving them. These guidelines are presented in sections 5.2.2.1 through 5.2.2.4.

5.2.2.1 Determining a Value for DELTA T - For most multipoint network applications, the default
value of 200 ms for DELTA T is adequate. The default value of 200 ms is the smallest permissible
value for DELTA T and represents the actual time required for the microcode to update the urgencies
of 12 tributaries. However, in specific cases a higher value of DELTA T might be recommended. An
example of this is a network formed by low traffic devices.

5-6

NOTE
The minimum polling interval defines the time required for a tributary to reach the urgency threshold
value of 128. This is the minimum time required to
be eligible for polling. The maximum polling interval

cannot be determined. This is because it is a function

of line speed, message traffic, the number of tribu-

taries in a network, and the polling states of those
tributaries. These variables make it impossible to
predict the time at which any tributary in a network

is polled.

ACTIVE
(NDM — INACT)

(TO — UNRSP)

(TO — DEAD)

MK-1856

Figure 5-4

State Diagram of Polling State Transitions

5.2.2.2 Determining Values for Q and R - For a given value of
DELTA T, the minimum polling interval is a function of the user-defined parameters Q and R. For example,
if a minimum polling interval of
3.2 seconds is desired for a tributary (assuming DELTA T = 200
ms), the parameters Q = 0, and R =
8 satisfy this requirement. With these values of Q and R, the
time to reach maximum polling urgency is

5-7

6.375 seconds (see Figure 5-2). Notice that if Q = 64 and R = 4, the minimum polling interval remains at 3.2 seconds but the maximum polling urgency increases to 9.55 seconds.
NOTE

Reaching maximum poiling urgency represents maximum eligibility for polling, but does not guarantee
that a tributary will be polled.

Figure 5-3 graphs the relationship between the default values of Q and R for each of the three polling
states. When all tributaries in a network have the default value for Q and R, and all tributaries are in
the active polling state, the manner of polling is round-robin.

5.2.2.3 Determining a Value for Poll Delay - The user-defined global parameter poll delay imposes a
fixed delay between control station polls. This provides a mechanism for regulating message traffic
without changing the values of Q and R for individual tributaries. During this delay, transmission from
the control station to tributaries is halted for the interval defined by the poll delay timer. This interval
begins when the tributary just polled deselects itself.

The ability to regulate message traffic through a single parameter is valuable in multipoint networks.
This is especially true where DMV 11s are configured together with slower character interrupt communication devices such as DUP11s. The value selected for poll delay in these circumstances is a function
of the character handling rates of the non-DMV11 devices.

In remote multipoint networks where the distance between the control station and tributaries varies
significantly, there is a greater chance of transmit and receive errors. This is due to the difference in
communication line settling time in such a network. In such instances, the settling time for the most
distant tributary station should be used for determining a value for poll delay.

For DMV l-implemented high-speed local networks, this parameter is unnecessary. The default value

(zero) for poll delay is used in these networks.

5.2.2.4 Determining a Value for DEAD T - This global parameter establishes the rate at which dead
tributaries are polled. Dead tributaries are polled on a round-robin basis, with one tributary polled at
each expiration of the dead tributary timer.

Polling dead tributaries can significantly impact network line utilization. The shorter the period of this
timer — the greater the impact. For a given value of DEAD T, the impact decreases as system line
speed increases. When determining a value for this parameter, the primary goal is to minimize the impact on network line utilization.

The value for DEAD T should be based on the period of the selection interval timer for the specific
application. For example, if the period of the dead tributary timer and the selection interval timer are
equal, only dead tributaries are polled. For most system applications, the period of the dead tributary
should be from three to ten times greater than that of the selection interval timer. This of course depends on line speed. The default value for DEAD T is ten seconds. This is about three times the default
value for the selection interval timer.

5.3

ERROR COUNTERS

In multipoint networks many tributaries tie to the same transmission line. Because of this, it is more
difficult to determine which link, if any, is causing errors. To aid in troubleshooting, the DMVIl maintains extensive error counters. Every DMV11 in the network (the control station and each tributary)
uses error counters to record errors. This allows user programs at any DMV11 in the network to determine overall error rates and to detect a malfunctioning link.
5-8

Data link errors are indicated to the DMV11 by DDCMP negative acknowledge messages (NAKs).
Each NAK contains an address field and a reason code that identifies the source and
reason for the
NAK. In general, when an error is detected in an incoming message, the station that
receives the message sends a NAK to the station that sent the message. By recording NAKSs sent and
NAKs received,
each point or tributary in the network is able to compile statistics on the condition
of the link established between the two stations. DDCMP error recording has been designed so that
even if one of the
stations on the link cannot record errors, the other station may be used to record errors
for all communications in both directions on the link.
'
There are three main categories of error counters used by the DMV11; data link counters,
station
counters, and threshold counters. Data link counters and threshold counters are
maintained for each
tributary/control station pair on a physical link. These counters are iocated in the tributary
status slots
of the data memory (Figure 5-5). Station counters are maintained for the physical link as a whole,
and
are located in the global status slots of the data memory (Figure 5-6). Unless otherwise stated,
all
counters increment to a maximum value and hold that value until cleared.

5.3.1
Data Link Error Counters
.
Data link counters are of two types; cumulative and background. The cumulative
counters are 8-bit
registers which latch at 255. The background counters are 16-bit registers which
latch at 65535. The
cumulative data link counters record and total all occurrences of an error and group
them into the following categories.
Data errors outbound,
Data errors inbound,
Local reply timeouts,
Remote reply timeouts,

Local buffer errors,
Remote buffer errors,

Selection timeouts.
Background data link counters are used to provide a statistical base for the cumulative
error counters
and therefore record:
e

The number of data messages transmitted,

The number of data messages received, and
The number of selection intervals.

A point-to-point station maintains a single set of data link counters. Multipoint stations
(control and
tributary) maintain a separate set of data link counters for each established tributary.
Data link

counters are cleared by:

e
®

A master clear of the DMVI1,
A control command to establish the tributary, or

A user-issued control command to read and clear the TSS error counters.

5.3.1.1
Data Errors Outbound - This 8-bit group counter records NAKs received for data errors
occurring on the communications channel outbound from this station. There are three
types of outbound
errors for which this counter records NAKSs received; header blockcheck (OHBCC), data field
blockcheck (ODBCC), and reply response (OREP). Three separate flag bits indicate which type
of outbound
error is being counted.

OHBCC (outbound header blockcheck) is set when a NAK with a reason code of one is received for a header block-check error for either data or control messages.

5-9

ODBCC (outbound data field blockcheck) is set when a NAK with a reason code of two is
received for a data field block-check error.

OREP (outbound reply response) is set when a NAK with a reason code of three is received
for a reply message response.

TRIBUTARY STATUS SLOT (TSS)
ADDRESS (OCTAL)

RESERVED

RECEIVE THRESHOLD ERRORS
6

TRANSMIT THRESHOLD ERRORS

SELECTION THRESHOLD ERRORS
7

DATA MESSAGES TRANSMITTED

—

DATA MESSAGES RECEIVED

—

SELECTION INTERVALS

—

DATA ERRORS OUTBOUND

RESERVED

OREP | ODBCC | OHBCC

DATA ERRORS INBOUND
RESERVED

IREP | IDBCC | IHBCC

LOCAL BUFFER ERRORS
RESERVED

LBTS

LBTU

RBTS

RBTU

IRTS

NRTS

REMOTE BUFFER ERRORS
RESERVED

SELECTION TIMEOUTS
RESERVED

LOCAL REPLY TIMEOUTS
REMOTE REPLY TIMEOUTS

MK-1860

Figure 5-5

Data Link and Threshold Error Counters

5-10

GLOBAL STATUS SLOT (GSS)
ADDRESS (OCTAL)

REMOTE STATION ERRORS

RSTR | RSEL

| RMHFE

|ROVRN

LOCAL STATION ERRORS
LOVR [ LUNDR | LMHFE | LOVRN

GLOBAL HEADER BLOCK CHECK
ERRORS

MAINT. DATA BLOCK CHECK ERRORS

MK-1859

Figure 5-6

Station Error Counters

5.3.1.2 Data Errors Inbound - This 8-bit group
counter records occurrences which normally result
from data errors on the communications channel inboun
d to this station. Three separate bits indicate
specific error types associated with this counter.
e

THBCC (inbound header blockcheck) is set when
messages having header-block check errors
are received. When this error occurs, point-to-point
stations and multipoint control stations
send a NAK with a reason code of one. A multipoint
control station records this error for the
selected tributary regardless of the address field
in the recejved message. A multipoint tributary records this error only if the address field matche
s its station address.
IDBCC (inbound data field blockcheck) is set when

be sent for data field block-check errors.
e

IREP (inbound reply response) is set when NAKSs

for a reply response.

3.3.1.3
®

nces which result from:

The loss of communications between two station

s while the one recording this error has data

The choice of an inappropriate value for the reply

Specifically, this error counter records the sending
5.3.1.4
®

with a reason code of three are to be sent

Local Reply Timeouts — This 8-bit counter records occurre

to transmit, or

timer.

of a REP message.

Remote Reply Timeouts — This 8-bit counter records occurre

nces which result from:

The loss of communications between two stations while

mit, or

NAKSs with a reason code of two are to

The choice of an inappropriate value for the remote

the remote station has data to trans-

station reply timer.

Specifically, this counter records ACKs sent in respons
e to a REP. The remote station sent a REP
because it received no acknowledgement for messag
es it previously sent. The local station received
those messages, but the remote station never received the
acknowledgement.

5-11

program at the station
5.3.1.5 Local Buffer Errors — This 8-bit counter records the fact that the user
s from the remote station.
recording the error failed to properly allocate receive buffers to data message

Two separate bits indicate the specific errors associated with this counter.

LBTU (local buffer temporarily unavailable) is set when a buffer is temporarily unavailable.

This condition indicates that a NAK with a reason code of eight is to be sent.

LBTS (local buffer too small) is set when a local buffer is too small for the incoming mes-

sage. This condition indicates that a NAK with a reason code of 16 is to be sent.

5.3.1.6 Remote Buffer Errors — This 8-bit counter records the fact that the user program at the remote
station failed to properly allocate receive buffers to data messages from the station recording the error.
Two separate bits indicate the specific errors associated with this counter.

RBTU (remote receive buffer temporarily unavailable) is set when a NAK with a reason

code of eight is received.

RBTS (remote receive buffer too small) is set when a NAK with a reason code of 16 is received.

§3.1.7 Selection Timeouts — This 8-bit counter records the occurrences which result from:
e

Loss of communications with a remote station,

Data errors on the communications channel to or from the remote station, and

The choice of an inappropriate value for this station’s select timer.

This counter is used only by half-duplex point-to-point or multipoint control stations. Two separate bits
indicate the specific errors associated with this counter.

NRTS (no reply to select) is used to record selection intervals in which no transmission is
received from the tributary, and no attempt to transmit is detected. Specifically, it records
the expiration of the select timer without the receipt of a valid control message or header, or
the detection of an attempted transmission.

IRTS (incomp'ete reply to select) is used to record selection intervals which were not proper-

ly terminated. Specifically, it records the expiration of the select timer preceded by receipt
of a valid control message, receipt of a valid header, or detection of an attempted transmission. An attempted transmission is indicated by:
—

The presence of a carrier signal,

—

The receipt of an SOH, ENQ, or DLE.

The receipt of a DDCMP synchronization sequence, and

5.3.1.8 Data Messages Transmitted — This 16-bit counter records messages transmitted by this station,
and latches at a count of 65535. It can be used as a statistical base when evaluating data errors outbound, local reply timeouts, and remote buffer errors. Messages sent as a result of retransmission are
not included in this count.

5.3.1.9 Data Messages Received — This 16-bit counter records messages received by this station, and
latches at a count of 65535. It can be used as a statistical base when evaluating data errors inbound,
remote reply timeouts, and local buffer errors. Messages received out of sequence or in error are not
included in this count.

5-12

3.3.1.10 Selection Intervals — This 16-bit counter records the number
of times this station selects the
other station. It also latches at a count of 65535. Specifically,
it records the number of messages transmitted with the select flag on. It is only used by half-duplex
point-to-point and multipoint control stations. It can be used as a statistical base when evaluating the number
of selection timeouts.

5.3.2 Station Error Counters
Station counters are 8-bit counters which latch at 255 and
rences may be the result of:

record unusual occurrences. These occur-

A hardware or software fault at this station,

A hardware or software fault at a remote station, or

A data error on the communications channels undetected

by the header block-check field.

A single set of these counters is used for all tributaries on a multipoin

t link.

N
-

There are four types of station counters:

Remote station errors,
Local station errors,
Global header block-check errors, and
Maintenance data field block-check errors.

Station counters are cleared by:
e

A master clear of the DMVI1I, or
A user-issued control command to read and clear the GSS error

counters.

5.3.2.1
Remote Station Errors - This 8-bit counter records occurrences caused
by a fault in a remote
station or by an undetected data error on the channel inbound to this
station. Four separate bits indicate
the specific errors associated with this error counter.
¢

ROVRN (remote receive overrun) is set when a NAK with a reason
code of nine is received
for a receive overrun.

RMHFE (remote message header format errors) is set when a message
is received which has
a header format error. This condition indicates that a NAK
with a reason code of 17 is to be
sent.

RSEL (remote selection address error) is set when a multipoin
t control station receives a

message containing an address field which does not
match the address of the currently se-

lected tributary. RSEL is a flag used only by multipoint control

stations.

RSTR (remote streaming tributaries) is set by either one of two
events: 1) an implementation-dependent maximum transmission interval is exceeded without
releasing the channel
(babbling tributary), or 2) the channel is not released following the
end of a selection interval
(streaming tributary).

5.3.2.2 Local Station Errors — This 8-bit counter records occurren
ces caused by a fault in a local station or by an undetected data error on the channel outbound from
this station. Four separate bits indicate the specific errors associated with this error counter.
¢

LOVRN (local receive overrun, NAK sent) is set for local station
receive overruns. This condition indicates a NAK with a reason code of nine is to be sent.

5-13

LOVR (local receive overrun, NAK not sent) is set by a receive overrun when a NAK is not
sent. For a multipoint tributary, this happens if an overrun occurs while receiving a header.
For other stations, this occurs when the station is not in the DDCMP run state.

LUNDR (local transmit underruns) is set when a transmit underrun occurs.

LMHFE (local message header format error) is set when a NAK with a reason code of 17 is

received to indicate a message with a header format error was sent by this station.

5.3.2.3 Global Header Block-Check Errors — This 8-bit counter records the occurrence of header
block-check errors that are not recorded on a per tributary basis. Specifically, it counts header blockcheck errors for maintenance messages and for messages to tributaries where the address field does not
match the station address.

5.3.2.4

Maintenance Data Field Block-Check Errors — This 8-bit counter records the occurrence of

data field block-check errors for maintenance messages.
Threshold Error Counters

5.3.3

Threshold error counters are used to determine if a persistent fault exists. A persistent fault is one
which occurs seven consecutive times. Whenever a threshold counter reaches its maximum value (7),
the user program is notified by a control response.

In the DDCMP run state, threshold counters are cleared when the user is notified. In this way the user
is continually informed of a persistent fault. In the DDCMP ISTRT and ASTRT states, threshold
counters are not cleared when the user is notified. In this way the user is not continually informed of an
inoperative remote station.

A point-to-point station maintains a single set of threshold counters. A multipoint control station maintains a separate set for each tributary. A multipoint tributary maintains a single set unless it supports
multiple tributary addresses in which case it maintains a single set for each established tributary address.

There are three types of threshold error counters: transmit, receive, and selection.

5.3.3.1

Transmit Threshold Errors - This 3-bit counter is incremented (if less than seven) in the fol-

lowing instances.

The DMVI11 is in the ISTRT state when a STRT message is sent,

The DMVI11 is in the ASTRT state when a STACK message is sent, or

The DMVI1I is in the run state and a NAK with a reason code other than three (REP response) is received, or when sending a REP message.

The transmit threshold error counter is cleared:
e

Upon entering the ISTRT, ASTRT, or run states.

While in the run state one of the following occurs:

—

A transmit threshold error is reported,

—

A NAK, ACK, or data message is received acknowledging a new message, or

A NAK, ACK, or data message is received when no messages are outstanding.
5-14

5.3.3.2 Receive Threshold Errors — This 3-bit counter is incremen
ted (if less than seven) when a NAK
with one of the following reason codes is sent.
Reason Code

Description

Header block-check error.
Data field block-check error.

3
8
9
16

REP response.
Buffer temporarily unavailable.
Receive overrun.
Message header format error.

This counter is cleared when:
e
®

Entering the ISTRT, ASTRT, or run states,
A control message with a correct header blockcheck is received
ror,

without a header format er-

A data message with correct header and data field blockche
cks is received without a header
format error, or

In the run state, a receive threshold error is reported.

5.3.3.3

Selection Threshold Errors - This 3-bit counter is only used by multipoin
t control stations and
half-duplex point-to-point stations. It is incremented (if less than
seven) when a selection timeout oc-

curs.

It is cleared upon receipt of a message with the select bit set, or while
in the run state and a selection
threshold error is reported.
5.4

DMV11 MICROCODE INTERNAL DATA BASE OVERVIEW
Functionally, the DMV11 internal data base provides the mechani
sm for managing

The assignment and completion of transmit and receive buffers,

The queuing of DMV11 responses,

The assignment of TSS structures to established tributaries for the

of tributary and global status information.

storage and maintenance

A map of this data base is shown in Figure 5-7. The data base is implemen

ted by three basic structures:

Linked lists,

e
e

Slot mapping table,
TSS and GSS structures.

Each of these are described below in terms of organization and
S5.4.1
Linked Lists
A linked list is an open-ended data list made up of fixed-length

function.

blocks linked by pointers. Each of these
blocks (link blocks), contain seven bytes of data and a one byte
pointer to the next link block in the list.
The pointer in the last block in the list is a terminator value. Figures
5-8 and 5-9 illustrate the standard
format for DMV11 linked-list structures.

HEXADECIMAL

0000

SCRATCH PADS

16 BYTES

Q-BUS CSRs

8 BYTES

SCRATCH PADS

32 BYTES

OUT NPR ADDRESS

3 BYTES

SCRATCH PAD

1 BYTE

IN NPR ADDRESS

3 BYTES

SCRATCH PAD

BYTE

GLOBAL STATUS SLOT

64 BYTES

SLOT MAPPING TABLE (SMT)

256 BYTES

MICROPROCESSOR STACK

64 BYTES

10
1B

3B
38

3C
3F

80
co

1FF

c00

BUFFER AND OUTPUT QUEUE

98 ENTRIES

8 BYTES/ENTRY

TRIBUTARY STATUS SLOTS
12 ENTRIES

64 BYTES/ENTRY

800
MK-2495

Figure 5-7

Data Memory Map

A DMVI11 linked list is made up of five kinds of linked lists.
1.

The free linked list — A list of empty link blocks used by the microcode to form the remaining
kinds of linked lists.

The response linked list — A queue of responses for posting to the user program.

The common buffer pool linked list — A list of the accessing information for each receive
buffer assigned to the common pool. There is one link block for each assigned buffer.
Receive buffer linked list — A list of receive buffer accessing information. One of these is
maintained by the microcode for each established tributary having private receive buffers

assigned. There is one link block for each buffer.

Transmit buffer linked list — A list of transmit buffer accessing information. One of these is
maintained by the microcode for each established tributary having transmit buffers assigned.
There is one linked list for each buffer.

§4.1.1 The Free Linked List - The free linked list from which all other linked lists draw link blocks, is
maintained in the lower section of data memory called the buffer and output queue (BOQ) (Figure 5intc a total of 104 link blocks available for use by the operational linked
7). These 832 bytes translate int
lists. In this way, the free linked list functions as a finite resource for the operational linked lists.
N\

TL.c~

O21

laey

5-16

LINK BLOCK
POINTER A

START OF LIST
POINTER

DATA

LINK BLOCK
POINTER B

DATA

LINK BLOCK
POINTER C

DATA

Ee——mJ

oE
oF
oN

377

TERMINATOR

DATA

MK-1981

Figure 5-8

DMV11 Linked List Structure Format

As previously stated, a linked list is equipped with two list pointers; one that points to the start of the
list and one that points to the end of the list. When a link block is removed from the free linked list, the
start of the list pointer is changed to point to the next available link block in the free linked list. When a
link block is completed by one of the operational linked lists, it is added to the end of the free linked list

and its internal pointer is set to the terminator value of 377 octal. In addition, the internal pointer in the
next to last link block is changed from 377 octal to the address of the link block just added. The startand end-of-list pointers for the free linked list are maintained in the station GSS.

5-17

Link blocks are removed from the free linked list and added to the receive, transmit, or common pool
buffer linked lists when the user program issues control or buffer address/character count commands
for that purpose. Similarly, link blocks are removed from the free linked list and added to the response
linked list when the DMV11 microcode posts a response to the user program. If the last link block is
removed from the free linked list, the start of the list pointer is set to the terminator value of 377 octal
to indicate there are no more link blocks available. In this event, the next request for a link block generates the fatal error QUEUE OVERFLOW. For this reason, the buffer allocation strategy for a user
program must be designed to assure an adequate number of link blocks.

LINK POINTER
MESSAGE NUMBER

POINTER TO THE NEXT LINK BLOCK
DDCMP MESSAGE NUMBER

BSEL 3

TRIBUTARY ADDRESS

BSEL 4

BUS ADDRESS

BSEL 5

BUS ADDRESS

BSEL 6

CHARACTER COUNT LOW

BSEL 7

CHARACTER CNT HIGH, BA16, BA 17

BSEL 2

TYPE CODE AND BA 18-21
MK-2497

Figure 5-9

Standard Link Block

5.4.1.2 The Response Linked List - This linked list functions as a queue of buffer disposition, control,
and information responses to be posted to the user program. The format of the link block for each of
these three responses is shown in Figure 5-8. When preparing a link to convey a control or information
response, the microcode clears all unused bit positions in the link block to zero. However, link blocks
restored to the free linked list remain unchanged.

The start-of-list and end-of-list pointers for the response linked list are maintained in the station GSS.

5.4.1.3

Buffer Linked Lists — A buffer linked list is provided for each type of message buffer allocated

by a user program. These are:

e
e

Common pool receive buffers,

Private receive buffers, and
Transmit buffers.

Each link block in a buffer linked list provides the location and size of a buffer in main memory.

The Common Buffer Pool Linked List — This linked list provides a queue of receive buffers available to
all established tributaries according to the quota assigned to each tributary.

Common pool buffers are assigned through the buffer address/character count command, and enabled
with tributary quota assignments through the control command (see Section 3.3.3). The start-of-list and
end-of-list pointers for this linked list are maintained in the station GSS.
Receive Buffer Linked List — This linked list serves as a queue of private receive buffers. One list is
maintained for each tributary established at a multipoint station. For point-to-point stations, one list is

maintained at each station. The start- and end-of-list pointers for each receive buffer linked list are
maintained in the associated tributary’s (or station’s) TSS.
5-18

Transmit Buffer Linked List — This list functions as a queue of transmit

buffers. One list is maintained
point stations, one list is maintained

for each tributary established at a multipoint station. For point-to-

at each station. The start- and end-of-list pointers for each
transmit buffer linked list are maintained in
the associated tributary’s (or station’s) TSS.

A unique feature of this link block is the message number field.
When a message 1s transmitted from a
buffer, the header of that message contains the DDCMP message
number (in the message number
field). The microcode uses this field to locate the buffer for
a message that has been NAKed after
transmission and, therefore, must be retransmitted.

5.4.2 Slot Mapping Table
Under DDCMP, the 8-bit message header address field

permits a maximum of 255 unique tributary
addresses in a multipoint network. However, the DMV11
microcode limits the number of established
tributaries to 12. In order to implement DDCMP, a tributar
y in a DMV11-based multipoint network
can have a TSS address in the range of 1 to 255. However
, only 12 of these tributaries may be established at any one time.
TSS addresses are assigned at both control and tributar
y stations through the slot mapping table
(SMT). As shown in Figure 5-7, this table occupies 256
locations in DMV11 data memory; one location
for each of the 255 possible tributary addresses, and one
location to address the GSS.
The function of the SMT is to map an 8-bit tributary address
tures. When a tributary is deleted, its TSS and SMT

into one of the 12 available TSS strucentry is released for reassignment. When 12 tribu-

taries are established and an attempt is made to establis

h a 13th, a procedural error is posted to the user

program.

5.4.3 TSS and GSS Structures
The TSS and GSS structures occupy separate sections

of data memory. The GSS is a single 64-byte
section while the TSS structure consists of twelve 64-byte
sections.

5.4.3.1

The Global Status Slot (GSS) - Functionally, the GSS is

Maintain control and status information specific to

Record event counts and error conditions that are global

Store global parameters.

used to:

the operation of the microcode,

in nature, and

The majority of the GSS is devoted to microcode control
and status information. A detailed map of the
GSS is shown in Figure 5-10.
Access to the GSS is accomplished on word boundar
ies. A user program can read any GSS location
through the control command. The content of the addres
sed location is transferred to the user program
through an information response. A user program can
read and clear only GSS station error counters.
The four global parameters (locations 34 through 37) are
written by the user program through the control command.

haibadis S

5.4.3.2 Tributary Status Slots (TSS) - A TSS contain
s four general categories of tributary information (Figure 5-11):
Protocol and tributary status,
Error and statistical counters,

Message exchange variables, and
Polling parameters.

5-19

Protocol and Tributary Status — This category includes information on the tributary’s protocol state, its
status with relation to the logical communications line, its protocol status, and its polling status. Tributary polling status is maintained only at a multipoint network control station. Although this information is only pertinent to, and used by the DMV11 microcode, it can be read by a user program.

Error and Statistical Counters — These counters provide the user program with a wide range of error
counts, and a set of statistical counts that permit analysis of the meaning of specific error counts. These
counters can be read and cleared by the user program. The function of each of these counters is described in detail in Section 5.3.

Message Exchange Variables — This category includes a range of variables used by the microcode to
control the transmission and reception of message data. This includes the common buffer pool quota
assigned by the user program.

A group of timers is also included in the message exchange variables. These timers can be preset to a
specific timeout value by the user program, and directly concern message traffic transferred on the
logical link by the associated tributary. These timers are referred to as:
Transmit delay timer,

Selection interval timer,*
Maximum transmitted message count,
Babbling tributary timer.

The link management functions performed by these timers is detailed in Chapter 4.

Polling Parameters — These parameters are user-defined values that are used by the polling algorithm
to conduct dynamic polling activity in multipoint networks. The functions performed by the DMV11
polling algorithm, and the criteria for determining the values for each parameter, are discussed in detail
in Section 5.2.

w*oa

)

A 1IMEouUtl vdiug 1ot

Al
o

ala~nsla

LINC >Cicvtiun

ap—

ed in each tributary’s TSS, but the actual timer is maintained in

the GSS.

5-20

GSS

ADDRESS

POLPTR

RCVPTR
1

RPM CNTR

XMTPTR

TSP

NASP

BUFPTR

S/OF

S/0Q

S/0C

(HIGH)

MODEM

UNUSED

CLEAR TO SEND TIMER (LOW)

REMOTE STATION ERRORS

RSTR | RSEL

TIMER STATUS

S/R TIMER (LOW)
7

ACKTIM

(HIGH)

E/OC

(LOW,

FLAG REGISTER "D~

E/OQ
5

ACKTIM

MODE

E/OF

(HIGH)

|RMHFE|ROVRN

LOCAL STATION ERRORS
LOVR | LUNDR| LMHFE | LOVRN

(HIGH])

B/CW TIMER (LOW)

GLOBAL HDR BCC ERRORS
MAINT DATA BCC ERRORS
MK-2489

Figure 5-10

Global Status Slot (Sheet 1 of 2)

5-21

GSS
ADDRESS

XHDR

(1)

POLL DELAY TIMER (LOW)
(HIGH)

(2)
21

(3)

DEAD SCAN

(4)

(5)

RCVHDR (1)

(3)

(5)

CARRIER WAIT

TIMER COUNTER

(4)
25

NUMBER OF SYNCS
RESERVED

(2)
24

CARRIER LOSS TIMER

USYRT HANG TIMER

(6)

POLL UPDATE POINTER

DELTAT

(HIGH)

(6)

R TIMER (LOW)

DEAD T

D TIMER (LOW)

(LOW)
(HIGH)

(HIGH)

(LOW)

POLL DELAY

(LOW)
(HIGH)

(HIGH)

MK-2480

Figure 5-10

Global Status Slot (Sheet 2 of 2)

5-22

TSS

ADDRESS

TRIB STATUS FLAGS

TRIB STATUS FLAGS
11

TRIBUTARY ADDRESS
POLL STATUS FLAGS

POLL RATE (Ri)

RESERVED

| COMMON POOL QUOTA

SELECTION THRESHOLD ERRORS
7

| DATA

IREP!

TRANSMITTED

IDBCC|

IHBCC

LBTS

LBTU

REMOTE BUFFER ERRORS

RBTS|

RBTU

SELECTION TIMEOUTS

RESERVED |

MESSAGES

OHBCC

LOCAL BUFFER ERRORS

RESERVED

TRANSMIT THRESHOLD ERRORS

o0DBCC|

DATA ERRORS INBOUND

RESERVED

RECEIVE THRESHOLD ERRORS
6

OREP|

RESERVED |

MAX MSG COUNTER
5

DATA ERRORS OUTBOUND

RESERVED|

POLL PRIORITY (Vi)

SELECTION

INTERVALS

POLL STATUS FLAGS

MESSAGES

RECEIVED

NAK REASON

DATA

IRTS|

NRTS

LOCAL REPLY TIMEOQUTS

REMOTE REPLY TIMEOUTS

MK-2722

Figure 5-11

Tributary Status Slot (Sheet 1 of 2)

5-23

TSS

1TSS

ADDRESS

N HIGHEST MSG NUMBER XMIT'D

DELAY TIMER

A HIGHEST MSG NUMBER ACK'D

T NEXT MSG NUMBER TO XMIT

X LAST MSG NUMBER XMIT'T

CX (CONTROL X REPLY T/0)

E/OX END OF XMIT BUFFER QUEUE
R HIGHEST MSG NUMBER RCV'D

S/OR START OF RCV BUFFER QUEUE

TRANSMIT

DELAY

[INACTIVE STATE

#NDM

-->

#T/0

--->

UMRSP

#T/0

--->

DEAD STATE

SELECTION INTERVAL
TIMING COUNTER

TIMER

VALUE FOR UMRSP

MAXIMUM MESSAGE COUNTER

E/OR END OF RCV BUFFER QUEUE
26

Q VALUE FOR UMRSP
R

S/DX START OF XMIT BUF QUEUE

Q VALUE FOR INACTIVE STATE

R VALUE FOR INACTIVE STATE

XPTR ADDR OF LNKBK FOR MSG X

Q VALUE FOR ACTIVE STATE

R VALUE FOR ACTIVE STATE

TPTR ADDR OF LNKBK FOR MSG T
22

PRESET VALUE FOR TRANSMIT

NO DATA MESSAGE COUNTER

BABBLING TRIBUTARY
TIMING COUNTER

T/O COUNTER

MK-2721

Figure 5-11

Tributary Status Slot (Sheet 2 of 2)

5-24

APPENDIX A
DDCMP

A.1

DDCMP

The Digital Data Communications Message Protocol (DDCMP

) provides a data link control procedure
that ensures a reliable data communication path between
communication devices connected by data.
links. DDCMP has been designed to operate over full- and
half-duplex synchronous and asynchronous
channels in both point-to-point and multipoint modes. It can
be used in a variety of applications such as
distributed computer networks, host front-end processors,
remote terminal concentrators, and remote
job entry-exit systems.
A.1.1
Controlling Data Transfers
The DDCMP message format is shown in Figure A-1.
Three control characters are provided in
DDCMP to differentiate between the three possible types of messages:

SOH - Data message follows,

ENQ - Control message follows,
DLE - Maintenance message follows.

Note that the use of a fixed-length header and message
size declaration obviates the requirement for
extensive message and header delimiter codes.

SYN|

|SYN|

| SOH

COUNT

|FLAG

DATA

|RESPONSE | SEQUENCE {ADDRESS|CRC-1

14 BITS

TS|2 BITS|8 BITS

8 BITS

|16 BITS

(ANY NUMBER OF 8-BIT

CRC-2

CHARACTERS UP TO 2'4) 16 BITS
MK-2248

Figure A-1

DDCMP Data Message Format

A.1.2

Error Checking and Recovery
DDCMP uses a 16-bit cycle redundancy check (CRC-16)
for detectin

error occurs, DDCMP sends a separate negative acknowl
edge (NAK)

quire an acknowledgement message for all data messages.

g transmission errors. When an
message. DDCMP does not re-

The number in the response field of a normal

header or in either the special NAK or acknowledge (ACK)
control message specifies the sequence
number of the last good message received. For example, if
messages 4, 5, and 6 have been received
since the last time an acknowledgement was sent and message
6 is bad, the NAK message specifies
number 5 which says “messages 4 and 5 are good and 6
is bad.” When DDCMP operates in full-duplex
mode, the line does not have to be turned around; the NAK
is simply added to the sequence of messages
for the transmitter.
When a sequence error occurs in DDCMP, the receiving station

transmitting station detects, from the response field of

A-1

does not respond to the message. The

the messages it receives (or via timeout), that

if the next
the receiving station is still looking for a certain message and sends it again. For example,
the
change
not
does
receiver
the
instead,
6
receives
message the receiver expects to receive is 5, but
up
messages
all
accept
“I
say,
will
receiver
The
.
response field (which contains a 4) of its data messages
through message 4 and I'm still looking for message 5.7
Character Coding

A.1.3

DDCMP uses ASCII control characters for SYN, SOH, ENQ and DLE. The remainder of the mes-

sage, including the header, is transparent.
rency

Data Transpa
length. The
DDCMP defines transparency by use of a count field in the header. The header is of a fixed
from 1 to
be
can
which
field,
on
informati
nt
transpare
the
of
count in the header determines the length
header
all
field;
CRC-16
a
by
followed
is
it
field,
count
and
16,383 bytes long. To validate the header
data
the
receive
to
used
is
count
the
,
validated
Once
on.
calculati
characters are included in the CRC
is
stuffing
character
Thus,
field.
data
the
on
d
calculate
is
which
and to locate the second CRC-16,

A.1.4

avoided.

Utilization

Data Channel
ex mode,
DDCMP uses either full-duplex or half-duplex circuits at optimum efficiency. In the full-duplThe
only
stream.
data
own
its
g
containin
each
channels,
one-way
nt
DDCMP operates as two independe
direction.
opposite
the
in
stream
data
the
in
sent
be
must
which
dgements
dependency is the acknowle
Separate ACK messages are unnecessary, therefore, reducing the control overhead. Acknowledgements
are simply placed in the response field of the next data message for the opposite direction. If several
can be
data messages are received correctly before the terminal is able to send a message, all of themopposite
the
in
acknowledged by one response. Only when a transmission error occurs, or when traffic

A.1.5

direction is light (no data message to send), is it necessary to send a special NAK or ACK message,
respectively.

In summary, DDCMP data channel utilization features include:

A.2

The ability to run on full-duplex or half-duplex data channel facilities,

Low control character overhead,

No character stuffing,

No separate ACKs when traffic is heavy; this saves on extra sync-characters and inter-

Multiple acknowledgements (up to 255) with one ACK, and

The ability to support point-to-point and multipoint lines.

message gaps,

PROTOCOL DESCRIPTION

or fullDDCMP is a very general protocol; it can be used on synchronous or asynchronous, half-duplexprotocols
duplex, serial or parallel, and point-to-point or multipoint systems. Most applications involving
are half-duplex or full-duplex transmissions in a serial synchronous mode; that operating environment is
emphasized in the following description.

The header is the most important part of the message because it contains the message sequence numbering information and the character count, the two most important features of DDCMP. Because of
the importance of the header information, it merits its own CRC blockcheck, indicated in Figure A-2 as

CRC-1. Messages that contain data, rather than just control information, have a second section which
contains any number of 8-bit characters (up tc a maximum of 16,383) and a second CRC (indicated in
Figure A-2 as CRC-2).

A-2

NOTE 1
V'S

SYN

CLASS

INFORMATION

COUNT [ FLAG

14 BITS|

|RESPONSE | SEQUENCE |ADDRESS | CRC

2 BITS

8 BITS

| ANY NUMBER | CRC 2

|16 BITS

OF 8-BIT

16 BITS

CHARACTERS

Nores~Yor, 2
SGH - DATA MESSAGES
ENQ{ ACKNOWLEDGEMENT

NEGATIVE ACKNOWLEDGE

REASONS:

REPLY MESSAGE

DLE

res .

Nore

OXXXXX

XXX XXX

XXXXXXXX

10000001

XXX
X

CHARACTER COUNT

XXXXXXXX

RESP #

MESSAGE#

ADDRESS

00000101

00000001 000000

RESP #

00000101

00000000

00000071 0Q---------

ADDRESS

RESP #

00000000

ADDRESS

BCC HEADER ERROR

000001

BCC DATA ERROR

000010

REP RESPONSE

000011

BUFFER UNAVAILABLE

001000

RECEIVER OVERRUN

001001

MESSAGE TOO LONG

010000

HEADER FORMAT ERROR

010001

00000101

ENQ { START MESSAGE

00000101

0000001 1000000

00000110000000

00000000

LSTMESS#

00000000

ADDRESS

00000000

ADDRESS

START ACKNOWLEDGEMENT

00000101

00000111000000

MAINTENANCE MESSAGE

00000000

10010000

ADDRESS

CHARACTER COUNT

00000000

ADDRESS

NOTES:

1. ONLY THE DATA MESSAGE AND THE MAINTENANCE
ONLY THESE MESSAGES HAVE THE INFORMATION
FORMAT DIAGRAM ABOVE.

MESSAGE HAVE CHARACTER COUNTS, SO
AND CRC2 FIELDS SHOWN IN THE MESSAGE

2. "RESP #" REFERS TO RESPONSE NUMBER. THIS
IS THE NUMBER OF THE LAST MESSAGE
RECEIVED CORRECTLY. WHEN USED IN A NEGATIVE
ACKNOWLEDGE MESSAGE, IT IS ASSUMED
THAT THE NEXT HIGHER NUMBERED MESSAGE WAS
NOT RECEIVED, WAS RECEIVED WITH
ERRORS, OR WAS UNACCEPTED FOR SOME OTHER
REASON. SEE “REASONS.”

3. "MESSAGE#" IS THE SEQUENTIALLY ASSIGNED
NUMBER OF THIS MESSAGE. NUMBERS ARE
ASSIGNED BY THE TRANSMITTING STATION MODULO
256; L.E., MESSAGE 000 FOLLOWS 255.
4. "LSTMESS#" IS THE NUMBER OF THE LAST MESSAGE
TEXT DISCUSSION OF REP MESSAGES.

TRANSMITTED BY THE STATION. SEE THE

5.” ADDRESS" IS THE ADDRESS OF THE TRIBUTA
RY STATION IN MULTIPOINT SYSTEMS AND IS
USED IN MESSAGES BOTH TO AND FROM THE TRIBUTAR
Y. IN POINT TO POINT OPERATION, A

STATION SENDS THE ADDRESS “1” BUT IGNORES THE
ADDRESS FIELD ON RECEPTION.

6. ”Q" AND “S” REFER TO THE QUICK SYNC FLAG BIT AND
THE SELECT BIT. SEE TEXT.
MK-2249

Figure A-2

DDCMP Message Format in Detail

Before the message format is discussed in greater detail, the message sequencing system should be explained because most of the header information is directly or indirectly related to the sequencing operation.

In DDCMP, any pair of stations that exchange messages with each other number those messages sequentially starting with message number one. Each successive data message is numbered using the next
number in sequence, modulo 256. Thus, a long sequence of messages would be numbered 1, 2, 3,...254,
255, 0, 1,...255. The first message sequence always starts with a number 1, and every sequence thereafter begins with a 0. The numbering applies to each direction separately. For example, station A might
be sending its messages 6, 7, and 8 to station B, while station B is sending its messages 5, 6, and 7 to
station A. Thus, in a multipoint configuration where a control station is engaged in two-way communication with ten tributary stations, there are 20 different message number sequences involved — one
sequence for messages from each of the ten tributaries to the control station, and one sequence for
messages from the control station to each of the ten tributaries.
Whenever a station transmits a message to another station, it assigns its next sequential message number to that message and places that number in the sequence field of the message header. In addition to
maintaining a counter for the sequentially numbered messages which it sends, the station also maintains
a counter of the message numbers received from the other station. It updates that counter whenever a
message is received with a message number exactly one higher than the previously received message
number. The contents of the received message counter are included in the response field of the message

being sent, to indicate to the other station the highest sequenced message that has been received.

When a station receives a message containing an error, that station sends a negative acknowledge
(NAK) message back to the transmitting station. DDCMP does not require an acknowledgement for
each message, as the number in the response field of a normal header (or in either the special NAK or
positive acknowledgement message ACK) specifies the sequence number of the last good message received.

When a station receives a message that is out of sequence, it does not respond to that message. The
transmitting station detects this from the response field of the messages which it receives; if the reply
interval expires before the transmitting station receives an acknowledgement, the transmitting station
sends a REP (reply) message. The REP message contains the sequence number of the most recent
unacknowledged message sent to the remote station. If the receiving station has correctly received the
message referred to in the REP message (as well as the messages preceding it), it replies to the REP by
sending an ACK. If it has not received the message referred to in sequence, it sends a NAK containing
the number of the last message that it did receive correctly. The transmitting station then retransmits
all data messages after the message specified in the NAK.

The numbering system for DDCMP messages permits up to 235 unacknowledged messages outstanding; a useful feature when working on high-delay circuits such as those using satellites. However,
the DMV 11 limits the maximum number of unacknowledged messages outstanding to be 127.
A.3

MESSAGE FORMAT

With the above background, it is now time to explore the various DDCMP message formats in full
detail, as shown in Figure A-2. The first character of the message is the class of message indicator,
represented in ASCII with even parity. There are three classes of messages; data, control, and maintenance. These are indicated by class of message indicators SOH, ENQ, and DLE, respectively. The next
in
two characters of the message are broken into a 14-bit field and a 2-bit field. The 14-bit field is used
field
CRC
header
the
follow
that
s
character
of
number
data and maintenance messages to indicate the
14-bit field
and form the information part of the message. In control messages, the first eight bits of the with
zeros.
filled
generally
are
bits
six
last
the
is;
it
message
are used to designate what type of control
NAK.
the
for
reason
the
specify
to
used
are
bits
six
last
the
where
The exception is in NAK messages
The 2-bit field contains the quick-sync and select flags.
A-4

The quick-sync flag is used to inform the receiving station that the message
will be followed by synccharacters; the receiver may wish to set its associated synchronous receiver hardware
into sync-search
mode and sync-strip mode. This reestablishes synchronization and syncs are
discarded until the first
character of the next message arrives. The purpose of this is to permit the
receiving station to engage
any hardware sync-stripping logic it might have and prevent it from filling
its buffers with sync-characters. The select flag is used to control link management in half-duplex or
multipoint configurations
where transmitters need to get turned on and off.
Link management is the process of controlling the transmission and reception
of data on links where
there may be two or more transmitters and /or receivers actively connected
to the same signal channels.
This is true of half-duplex point-to-point links, as well as full- and half-duplex
multipoint links. On halfduplex links, only one transmitter may be active at a time: on full-duplex iinks,
oniy one siave transmitter may be active on the link at a time.

A station on such a link may transmit when it has been selected or granted
ownership of the link. This
ownership is passed by use of the select flag existing in all messages.
A select flag set in a received
message allows the addressed station to transmit after completing
reception of the message. The select
flag also means that the transmitter ceases transmitting after the message
is sent.

The response field contains the number of the last message correctly received.
messages and in the positive and negative acknowledge types

evident from the preceding discussion of sequence control.

The sequence field is used in data messages and in the REP type of
it contains the sequence number of the message as assigned by the

sage, it is used as part of the question, “Have you received all

(specify) correctly?”

This field is used in data

of control messages. Its function should be

control message. In a data message,

transmitting station. In a REP mesmessages up through message number

The address field is used to identify the tributary station in multipoin
both to and from the tributary. In point-to-point operation, each

t networks and is used in messages
station uses an address of 1.

In addition to the positive and negative acknowledgement and REP
types of control messages, there are
also start and start acknowledge control messages. These are used
to place the station which receives
them in a known state. In particular, they initialize the message
counters, timers, and other counters.
The start acknowledge message indicates that this has been
accomplished.
Figure A-2 also shows the maintenance message. This is typically

a bootstrap message containing load

programs in the information field. A complete treatmen
t of maintenance messages and start-up pro-

cedures is beyond the scope of this book.

NOTE
Refer to the DDCMP specification order (AAD399A-TC) for a complete detailed description of

DDCMP.

APPENDIX B
FLOATING DEVICE CSR AND
INTERRUPT VECTOR ADDRESSES

B.1
FLOATING DEVICE CSR ADDRESSES
UNIBUS and LSI-11 addresses, starting at 760010 and continuing through 763776, are designated as
floating device addresses (see Figure B-1). These are used as register addresses for communications (and

other) devices interfacing with the PDP-11 system (refer to Table B-1).

NOTE
Some devices are not supported by LSI-11; however,
the same scheme applies. That is, gaps are provided
as appropriate.

The rules for assigning device CSR addresses are as follows:
1.

Device and gap addresses are assigned according to the octal modulus as follows:

Devices with an octal modulus of 4 are assigned an address on a 4g boundary (the two
lowest order address bits = 0).

Devices with an octal modulus of 10 are assigned an address on a 10g boundary (the three
lowest order address bits = 0).

Devices with an octal modulus of 20 are assigned an address on a 20g boundary (the four
lowest order address bits = 0).

Devices with an octal modulus of 40 are assigned an address on a 403 boundary (the five
lowest order address bits = 0).

A gap, assigned according to Rule 1, must be allowed after the last device of each type.

A gap, assigned according to Rule 1, must be allowed for each unused rank on the list if a
device with a higher address is given.

Multiple devices of the same type must be assigned contiguous addresses.

If extra devices are added later to the system, the floating addresses may have to be reassigned
in agreement with Rules 1 through 4.

B-1

777 777

DIGITAL EQUIPMENT

WORDS

CORPORATION
(FIXED ADDRESSES)

770 000

DR11-C

767 777

1K
WORDS

1
USER ADDRESSES

764 000
763 777

)

WORDS

FLOATING ADDRESSES
DIGITAL EQUIP CORP (DIAGNOSTICS)

760 010
760 006
760 000
757 777

001 000

000 777

VECTORS

FLOATING VECTORS
000 300

000 277

TRAP & INTERRUPT

VECTORS

VECTORS
000 000

MK-2190

Figure B-1

UNIBUS and LSI-11 Address Map

B-2

Table B-1

Floating Device CSR Address Assignments

Size
Rank

Modulus

Device

(Decimal)

(Octal)

]

DJI11

DHI11

DQl1

DUI1I, DUVII

DUPI1

LKITA

DMCI11/DMR11

DZ11/DZV11, DZSI1,

10 (DMC before DMR)
10 (DZ11 before DZ32)

DZ32

KMCI11

RESERVED

VMV21

VMV3]

DWR70

RL11, RLVI1I

10 (after first)

LPA11-K

20 (after first)

KW11-C

RESERVED

RX11/RX211

10 (after first)

RXV11/RXV2]
19

DR11-W

(RX11 before RX211)

DR11-B

DMPI11

DPVI11

ISB11

10 (after second)

DMVI11

DEUNA

10 (after first)

MSCP (disk)

4 (after first)

DMF32

KMSI11

VS100

MSCP (tape)

4 (after first)
20

KMV11

DHVI11, DHU11

DMZ32

RESERVED

100

RESERVED

ADVI11-C

AAVII-C

AXVI1I1-C

KWV11-C

ADVI11-D

AAVII-D

NOTES:
1.

DZI11-E and DZ11-F are treated as two DZ11 devices.

Note that the units of the size and octal modulus fields are words and bytes, respectively.

B-3

B.2

FLOATING INTERRUPT VECTOR ADDRESSES

Interrupt vector addresses, starting at 300g and proceeding upward to 777g, are designated as floating
vectors. These are used for communications (and other) devices that interface with PDP-11 and VAX-11
systems (refer to Table B-2).
NOTE
Some devices are not supported by LSI-11; however,
the same scheme applies. Vector size is determined
by the device type.
The rules for assigning vector addresses are as follows:

Each device occupies vector address space equal to the vector size as illustrated in Table B-2.
For example, the DMR11 has a vector size of 4,g and occupies four vector address locations. If
the DMR11 vector address was 300g, the next available vector would be 310g.

There are no gaps except those needed to align an octal modulus.

Multiple devices of the same type would be assigned vectors sequentially.

Table B-2

Floating Interrupt Vector Address Assignments
Vector Size

Modulus

Rank

Device

(Decimal)

(Octal)

DCl11

TUS8

10 (See Note 1)

KL11

DL11-A

DL11-B

DLV1I1-]

DLVI11, DLVI1I1-F

3
4

DP11
DMI11-A

4
4

10
10

DNI11

6
7
8
9
10
11

DM11-BB/BA
DH11 modem control
DR11-A
DR11-C, DRV11
PA611 (reader+punch)
LPDI1

2
2
4
4
8
4

4
4
10
10
10
10

DX11

14
14
14
15
16
17
17
18
19
2

DL11-C
DL11-D
DL11-E/DLV11-E
DJ11
DH11
GT40
VSV11
LPS11
DQ11
KWI1L-W, KWV1l1

4
4
4
4
4
8
8
12
4
4

10
10
10
10
10
10
10
10
10
10

DUI11, DUVI11

DUPI1

23
24
25

DV11+modem control
LK11-A
RESERVED

6
4
4

10
10
i0

DTO07

Table B-2

Floating Interrupt Vector Address Assignments (Cont)

Vector Size

Modulus

(Decimal)

(Octal)

Rank

Device

DMCI11

DMRI11

10 (DMC before DMR)
10 (DZ11 before DZ32)

DZ11/DZS11/DZV11, DZ32

KMC11

RESERVED

VMV21]

VMV3]

VTVO01

DWR70

RLI11/RLVI1

TS11, TURO

4 (after first)

LPAI11-K

4 (after first)

IP11/IP300

4 (after first)

KWI11-C

RX11/RX211
RXV11/RXV2]

4 (after first)

DR11-W

4 (after first)

(RX11 before RX211)

DR11-B

DMPI11

DPVI11

4 (MASSBUS device)

MLI11

ISB11

DMV11

10
4 (after first)

DEUNA/DEQNA

MSCP (disk)

DMF32

4 (after first)

4
10

KMSI11

PCLI11-B

VS100

MSCP (tape)

KMVI11

4 (after first)

KCT32

IEU11/IEQI11

DHVI11, DHUI11

DMZ32

RESERVED

1
4
4

RESERVED

4 (after first)

RESERVED

ADV11-C

AAVI1I-C

AXV11-C

10 (after first)

KWVI11-C

ADVI11-D

AAV1I-D

RESERVED

DRVI1I1-J

NOTES:
1.

There is no standard configuration for systems with both DC11 and TUS5S.

A KLI11 or DLI11, used as the console, uses a fixed vector.

Note that the size field is in words (two words per interrupt vector), while the modulus field is in

bytes.

B.3 EXAMPLE OF DEVICE CSR AND INTERRUPT VECTOR ADDRESS ASSIGNMENT
The following example has devices that require device CSR and vector address assignments in the floating
address space. These devices are:
e

One DUII,

e
e

One RLI11, and
Two DHUI devices.
Interrupt

Address

Vector

Device

(Octal)

DJ11
DH11
DQ11

760010
760020
760030

DU11

760040

DUPI11
LKI11A
DMCl11
DZ11
KMCI11

760060
760070
760100
760110
760120

Gap for DUP11
Gap for LK11A
Gap for DMCI11
Gap for DZ11
Gap for KMCI1

RESERVED
VMV21
VMV3l1
DWR70
RLV11

760130
760140
760160
760170
760200

RESERVED Gap
Gap for VMV21
Gap for VMV31
Gap for DWR70
Gap for RLV11

RL11

760210

LPA11-K
KWI11-C
RESERVED
RX11

760220
760230
760240
760250

Gap for LPA11-K
Gap for KW11-C
RESERVED gap
Gap for RX11

DR11-W
DR11-B
DMP11
DPV11
DPV11

760260
760270
760300
760310
760320

Gap for DR11-W
Gap for DR11-B
Gap for DMP11
Gap for 1st DPVI11
Gap for 2nd DPV11

ISB11
DMV11

760330
760340

Gap for ISBI11
Gap for DMV11

DEUNA
UDASO
DMF32

760350

Gap for DEUNA

760354
760400

Gap for UDASO
Gap for DMF32

KMSI11

760420

Gap for KMS11

VS100
RESERVED

760440
760444

Gap for VS100
RESERVED gap

DUI11

760050

Comment

Gap for DJI1
Gap for DH11
Gap for DQI11
300

Gap for 2nd DU11

310

KMV11

760460

DHUI11

760500

320

Gap for KMV11

1st DHU11

DHU11
DHU11

760520
760540

330

2nd DHIJ11
Gap for 3rd DHU11

B-6

The first floating address is 760010. As the DJ11 has a modulus of 10g, its gap can be assigned to 760010.
The next available location becomes 760012.
As the DHI11 has a modulus of 20s, it cannot be assigned to 760012. The next modulo 20 boundary is
760020, so the DH11 gap is assigned to this address. The next available location, therefore, is 760030.
A DQI1 has a modulus of 10g, it cannot be assigned to 760022. Its gap, therefore, is assigned to 760030.
The next available location becomes 760032.
A DUII has a modulus of 10g; it cannot be assigned to 760032. It, therefore, is assigned to 760040. As

the vector size of the DU11 is four words, the next available address is 760050.

There is no second DUI1, so a gap must be left to indicate that there are no more DU11 devices. As
760050 is on a 10g boundary, the DU11 gap can be assigned to this address. The next available address is
760052.

and so on...

APPENDIX C

MODEM CONTROL REGISTER FORMATS

C.1
MODEM CONTROL REGISTER FORMATS
The modem signals made available by the DMV11 can be examined or modified
by the user program if
needed. This supplies the flexibility needed to meet the various modem interface
requirements of different countries.
READ MODEM STATUS

BSELA4:
Bit

Name

CARRIER

Description
Received line signal detector, commonly referred to as carrier detect, indicates that there is an appropriate audio tone being received from the remote modem. Typically, in full- and half-dupl-

ex
applications,
carrier
detect
is
on
whenever
the
communications line is intact and the remote modem has the sig-

nal request to send asserted (the modem is transmitting). This
signal is also applicable to the DMV11 integral modem.
1

NOT USED

ALWAYS READ AS ZERO.

CLEAR TO SEND

This signal is generated by the local modem to indicate whether

or not it is ready to transmit data. Clear to send is the local
modem’s response to the asserting of request to send. This signal
has a slightly different meaning with different modems. With
some modems it indicates that the carrier is being received from
the remote modem, and, therefore, is an indication that a suitable

communications channel exists.

MODEM READY

This signal indicates that the modem is ready to operate. The ON

condition indicates that the local modem is connected to the com-

munications line and is ready to exchange further control signals
with the DMV11. The OFF condition indicates that the local
modem is not ready to operate. This signal, when implemented by

the modem, is used by the DMVI11 to detect either a power-off
condition or a cable-related modem malfunction.
4

HALF-DUPLEX

This signal, when asserted, indicates that the DMV11 is in the
half-duplex mode. This means that the DMV11 is connected to a

communications line designed for transmission in either
direc-

tion, but not in both directions simultaneously. When cleared,
it
implies full-duplex operation which is two-way independent transmission in both directions.

C-1

Bit

Name

Description

REQUEST TO SEND

This signal serves to control the data channel transmit function of
the local modem, and on a half-duplex channel, to control the direction of data transmission of the local modem. On a fuil-dupiex
channel, the ON condition maintains the modem in the transmit
mode, and the OFF condition maintains the modem in the nontransmit mode. On a half-duplex channel, the ON condition
maintains the modem in the transmit mode and inhibits the receive mode. The OFF condition maintains the modem in the receive mode. A transition from OFF to ON instructs the modem to
enter the transmit mode. The modem responds by taking such action as may be necessary and indicates completion of such actions
by asserting clear to send, thereby, indicating to the DMV11 that
data may be transferred across the communications channel. A
transition from ON to OFF instructs the modem to complete the
transmission of all data that was previously transferred to the
modem and then assume a nontransmit or receive mode, whichever is appropriate. The modem responds to this instruction by
turning OFF the signal clear to send when it is again prepared to
respond to a subsequent ON condition of request to send.

DATA TERMINAL

This signal controls the switching of the local modem to and from
the communications line. When asserted, this signal serves to inform the local modem that the DMV11 is ready to operate. This
signal also prepares the modem for connection to the communications line and maintains this connection as long as it is ON.
When turned OFF, this signal causes the local modem to disconnect after all data previously transferred to the modem has
been transmitted. This signal can be used by the local modem to
detect a power-off condition in the DMVI11 or a cable-related

READY

modem malfunction.

RING

This signal indicates whether an incoming call signal is being received by the local modem. When ON, this signal indicates that
an incoming call (ringing) signal is being received by the local
modem. The ON state of ring must appear approximately at the
same time as the ON segment of the ringing cycle (during rings)
on the communications line. The OFF condition must be maintained during the OFF segment of the ringing cycle (between
rings) and at all other times that ringing is not being received.
This signal is not affected by the state of data terminal ready.

READ MODEM STATUS
BSELS

Bit

Name

Description

MODE

This bit indicates the operational mode of the line unit. A one indicates character-oriented protocol operation, and a zero inAwierwr

waw

weewaawW

this bit to one.

C-2

Bit

Name

Description

NOT USED

ALWAYS READ AS ZERO.

TEST MODE

This signal indicates whether or not the local modem is in a test
condition. (This signal applies only to modems that support this
feature.) When in the ON condition, this signal indicates to the
DMV11 that the local modem has been placed in a test condition.
The ON condition can also be in response to either local or remote activation by means of any other modem test condition. Activation of a telecommunications network test condition (for example, facility loopback) that is known to the modem can also

cause this signal to be ON. In the OFF condition, this signal indicates that the modem is not in the test mode and is available for
normal operation.
NOT USED

ALWAYS READ AS ZERO

NOT USED

ALWAYS READ AS ZERO

NOT USED

ALWAYS READ AS ZERO

NOT USED

ALWAYS READ AS ZERO

NOT USED

ALWAYS READ AS ZERO

WRITE MODEM CONTROL
BSEL4
Bit

Name

NOT USED

Description

SELECT STANDBY

Defaulted to 0 by DMV11 hardware.

MAINTENANCE
MODE 2

Defaulted to 0 by DMV11 hardware.

MAINTENANCE

Defaulted to 0 by DMV11 hardware.

MODE 1
HALF-DUPLEX

The DMV11 uses this bit to place the line unit into the half-duplex mode. The user program cannot set or clear this bit. The
DMVI11 can change line characteristics only through the mode
definition command. The DMV11 is equipped with a software interlock that prevents simultaneous transmission and reception
when in the half-duplex mode. While the transmitter is transmitting, the receiver is disabled from receiving data via a hard-

ware interlock.

SELECT
FREQUENCY

‘

This signal is used to select the transmit and receive frequency

bands of a modem. In the ON condition, the higher frequency

C-3

Bit

Description

Name

band is selected for transmission to the communications channel,
and the lower frequency band is selected for reception from the
communications channel. When OFF, the lower frequency band
is selected for transmission to the communications channel, and
the higher frequency band is selected for reception from the communications channel.
NOTE

The modem, if it supports select frequency, must be
set up to ignore this signal from DMV11.

DATA TERMINAL
READY

This signal controls switching of the local modem to and from the
communications line. When asserted, this signal serves to inform

the local modem that the DMV11 is ready to operate. This signal
also prepares the modem for connection to the communications
line and maintains this connection as long as it is ON. When
turned OFF, this signal causes the local modem to disconnect after all data previously transferred to the modem has been transmitted. This signal can be used by the local modem to detect a
power-off condition at the DMVI11 or a cable-related modem
malfunction.

NEW SIGNAL

This signal determines whether or not the local modem will rapid-

ly respond to new data on the communications line. This signal is
used at control stations in multipoint networks where the remote
modems operate in switched-carrier mode. This incoming signal
to the control station appears as a series of short message bursts
transmitted by each tributary as it responds to the poll from the
control station. In order to permit rapid accommodation to signals from several tributaries appearing in quick succession, the
control station informs the local modem when a new signal is
about to begin by asserting polling for a brief interval. For synchronous systems, clock timing on the incoming message varies
from message to message because the remote modems are in no
way synchronized to each other. If the time interval between mes-

sages is too short, the clock holdover after the end of one message
may preclude rapid synchronization on the following message.
The use of this signal allows the control station to reset the
modem receiver timing recovery circuit, enabling it to respond
more quickly to the line signal present after polling has been
turned OFF. This signal applies only to modems that support polling.

C.2 RS-449 VERSUS RS-232-C

The most common interface standard in use during recent years is RS-232-C. However, when used in
modern communications systems it has critical limitations; the most serious being speed and distance.
For this reason, the interface standard RS-449 was developed to replace RS-232-C. This standard maintains a degree of compatibility with RS-232-C to accommodate an upward transition to RS-449.
The most significant difference between RS-449 and RS-232-C is the lect ical characteristics of signals used between the data communications equipment (DCE) andthe data terminal equipment
C-4

(DTE). The RS-232-C standard specifies only unbalan
ced circuits, whereas, RS-449 specifies both balanced and unbalanced circuits. The specifications for these
two circuit types supported by RS-449 are
contained in EIA standards RS-422-A for balanced circuits
and RS-423-A for unbalanced circuits.
These new standards permit greater transmission speeds
and allow greater distance between the DTE
and DCE. The maximum transmission speeds supported
by RS-422-A and RS-423-A specified circuits
vary with circuit length. The normal transmission speed
limits are 20K b/s for RS-423-A at 61 m (200
feet) and 2M b/s for RS-422-A also at 61 m (200 feet). These
normal transmission speeds can be varied

by tradeoffs between speed and distance.

Another major difference between RS-449 and RS-232-C

accommodate the leads required to support additio

is the specification of two new connectors to

nal circuit functions and the balanced interface cir-

cuits. One connector is a 37-pin cinch used to accommodate
the majority of data communications applications. The other is a 9-pin cinch for applications requiri
ng secondary channel functions. Some of the
new circuits implemented by RS-449 support local
and remote loopback testing and standby channel
selection.
The transition from RS-232-C to RS-449 will not happen
immediately. Therefore, applications that require connection between RS-232-C and RS-449 interfac
es must adhere to the limitations of RS-232-C,
which specifies a normal transmission speed of 20K
b/s at a maximum distance of 15.2 m (50 feet).
DMV11 does not support RS-422-A balanced circuits
.

C-5

APPENDIX D
MODEM CONTROL

D.1
MODEM CONTROL
There are two ieveis of modem control available to the DMV11. The first
level is provided by the hardware, and the second by the DMV11 microcode.
D.1.1 Hardware Modem Control
The DMV11 provides the following modem control function:
e

Prevention of simultaneous transmission and reception in half-duplex

mode.

Half-Duplex Mode — When set, HALF-DUPLEX specifies that the DMV11
is in the half-duplex mode.
In half-duplex mode, a hardware interlock prevents the DMV11 from
transmitting and receiving simultaneously.
NOTE
This hardware lockout prevents the DMV11 from
being used in the half-duplex mode on a full-duplex
modem with the continuous carrier option installed.

D.1.2 Modem Control Implemented by the DMV11 Microcode
The modem control signals implemented by the DMV11 are:
Modem ready (data set ready),
Request to send/clear to send,

Carrier,

Data terminal ready, and
Auto answer.

Each of these signals are outlined in Table D-1.

Once modem ready goes ON, the DMV11 reports any transition from ON to OFF
to the user program
by issuing a control response containing the code for the system-event modem
disconnect. The microcode tests that modem ready is OFF for 10 ms. Transmission is initially
inhibited by the microcode by
interlocking the signals modem ready and request to send.
Whenever the signal carrier detect is dropped by the modem for greater than
program is notified by a control response containing the code for the system

1.28 seconds, the user

event modem carrier loss.

Diagrams are used in the discussion of modem control functions. Refer to
Figure D-1 as an aid in interpreting these diagrams. The flow depicted by the diagrams (Figures D-2 through D-8) describes the
processing of EIA modem control signals by the DMV11. Each diagram represents
a serial flow for a specific modem control function. However, the functions performed, as represent
ed by each diagram, are
performed in parallel. The readable and writeable modem signals listed on
the diagram for modem sta-

tus can be read and written through the control command using the request

and write mode control.

keys read modem status

Table D-1

Signal

Data Set ReadyModem Ready:

DMV11 Modem Control Functions

Description

Software interlock prevents the DMV11 from transmitting if DSR is not

returned. If DSR drops (meaning that it once was asserted) for a period
of 10 ms, the transmitter and receiver are resynchronized, the transmitter

and receiver sections of the microcode are reset to the idle state to allow
the user to return buffers, DTR is then dropped to clear the line (see
DTR for reasserting conditions), and the user is then notified of the DSR
drop via a control-out for disconnect.

Software interlock preventing the DMVI11 from transmitting if DSR is

not returned: If the DMV11 has been instructed by the user to start up
the communications line, and DSR is not asserted, the DMV11 does not
transmit. There is no timer started for the first assertion of DSR. It is the
responsibility of the user to ensure that the modem is plugged in. Also, if
the modem is a dial-up modem, the user should make sure that the number is dialed. In most cases the start command is issued with the intent of
waiting for an incoming call. In this case, the timer value is arbitrary so
that it has been left up to the user software to determine this timeout. If
data terminal ready (DTR) is not asserted because of a past error condition that caused the dropping of DTR (that is, disconnect), the user program may assert DTR via the write modem command to enable transmission.

Request to Send/
Clear to Send:

For all applications: Before RTS is asserted (if already asserted this is
bypassed) CTS is checked for the “ON” condition. If CTS is “ON”, a
10-20 ms timer is started while waiting for CTS to drop. If CTS does not
drop within the timer period, constant CTS is assumed and RTS is set.
For all applications: Software interlock prevents transmission if CTS is
not returned. IF CTS is not returned within 30 seconds (plus or minus 10
ms), a disconnect control-out is queued with a CTS failure code in
BSEL7. The transmitter and receiver are resynchronized, the transmitter
and receiver sections of the microcode are reset to the idle state to allow
the user to return buffers, and DTR is then dropped to clear the line. (See
DTR for reasserting conditions).

For all applications: During the time that RTS is set, every 10 ms CTS is
checked for the “ON” condition. If CTS stays in the “OFF” condition for
30 seconds (plus or minus 10 ms), a disconnect control out is queued with
a CTS failure code in BSEL7. The transmitter and receiver are resynchronized, the transmitter and receiver sections of the microcode are
reset to the idle state to allow the user to return buffers, and DTR is then
dropped to clear the line. (See DTR for reasserting conditions).
For all half-duplex applications: The setting of request to send is “ANDED” with the half-duplex bit in the hardware to “blind” the receiver

when transmitting.

Table D-1

Signal

Carrier:

DMYV11 Modem Control Functions (Cont)

Description

Software interlocks prevent transmission in half-duplex if carrier is in the

“ON?” condition. This prevents the DMV11 from running half-duplex on
four-wire constant carrier modems.
For all applications: Hardware interlock of carrier and the receiver clock
stop the USYRT from receiving if carrier were to drop in the middle of a
messaoe

For all applications: If carrier “dropsTM while the DMV11 is in the process
of receiving the carrier, the loss timer is started. If the carrier loss timer
expires (1.28 second interval), the user is notified via a control-out for

carrier loss. The receiver is then resynchronized and the receiver microcode is reset to the waiting state for the next message. If the carrier loss is

less than 1.28 seconds (carrier is reasserted before the timeout), the message being received is allowed to finish. If CRC errors are detected (normal case), the protocol recovers from the failure.

Data terminal ready:

DMV11 clears DTR on a power-up bus initialization, and a master clear.
This is a hardware function. DTR is not gated from the interface drivers
when the DMV11 is placed in loopback mode. DTR is monitored by diagnostics running in internal loopback to ensure that the microcode does not

set it.

When DTR is dropped because of errors, it is only reasserted if any of the
following conditions exist: auto answer is enabled or remote load detect is
enabled. The code is in the process of power-on boot or request boot.

Auto Answer:

This option is switch selectable. If enabled, the DMV11 asserts DTR and
waits for modem ready (DSR). Because of the difference between
modems in the U.S. and other countries, ring is not used as an indication
that an incoming call has been established. As it stands, DSR is the in-

dication that the call has been established. If a valid DDCMP message is
not received within 30 seconds (plus or minus 10 ms) after a connection is
established, DTR is dropped (hang up the phone). The connection is considered to be established on assertion of carrier or clear to send. The
transmitter and receiver are resynchronized, the transmitter and receiver
sections of the microcode are reset to the idle state, and DTR is then reasserted after DSR drops (or in 10 seconds whichever comes first). In this
case the user is not notified of the cancelled call. An internal counter is
incremented tc log the incoming calls (latches at 256) and is available for
reading by the user program.

CONDITIONS TO BE SATISFIED. IF CONDITIONS ARE NOT
MET SERIAL FLOW DOES NOT CONTINUE.

ACTIONS PERFORMED BY DMV11.

)

ENTRY OR EXIT SYMBOLS

MK-2657

Figure D-1

Flow Diagram Symbology

D-4

POWER ON

SYSTEM

[2.4]

POWER ON

INITIALIZATION

124

CLEAR DTR

] (2.5]

BOOT ENABLED

DEVICE

MASTER CLEAR (2:4]

(SWITCH)

USER ISSUES

MODE DEFINED

MODE DEFN

BOOT

IN SWITCHES

Brser

(26

COMMAND
[2.2]

(2.2]

SET DTR

SET CALTMR

= ON

\_/

seTemor

(23]
A

USER REQUEST

CALTMR

MODEM STATUS

= ON

READ/WRITE

DSR = ON

DSR = ON
CD = ON

psa=o0N
7

2.1]

L——:
MODSTAT

(

camr

SCAN FOR
REMOTE

LOAD

)

MESSAGE
VALID

MESSAGE

(2.3]

@}—_{

MESSAGE TO

OSR = ON TO

SENT

OFF

SET P/MOP 1

RECEIVE )

FOR

10mSEC

1
NOTIFY USER OF

P/MOP = ON

P/MOP = OFF

DSR DROP

DISCONNECT

——@

(CONTROL RESPONSE)
y

CTRANSMITZ)

L——»{

TRANSMIT

)

NOTES:

[2.1] REMOTE LOAD DETECT IS A MAINT. DDCMP MESSAGE INITIATING A DOWN LINE LOAD.
[2.2] CALTMR

- (CALL TIMER): USED TO DETERMINE IF VALID MESSAGE IS RECEIVED. "ON"” INDICATES TIMER

RUNNING.

[2.3] P/MOP - PRIMARY MAINTENANCE OPERATION PROTOCOL, REQUESTING REMOTE LOAD.
[2.4] RUN COMPLETE MICRODIAGNOSTICS (MICROPROCESSOR AND LINE UNIT)

[2.5] HARDWARE FUNCTION
(2.6] INVOKE PRIMARY MOP BOOT (BIT FIVE, BSEL 1)
MK-2705

Figure D-2

Modem Control (Start)

D-5

TRANSMIT

HALF-DUPLEX

FULL-DUPLEX

RECEIVER NOT

NO LINE ERRORS

LINE ERRORS

ACTIVE

ENCOUNTERED

CARRIER WAIT

TIMR =1 SEC

3.1
By

—

cLearRrTs

{

CD = OFF

CWTIMR

AsserTRTS

[ c1S TIMER -1 SEC |
| 132
{

;

'_r_

CTS TIMR <«—

CTS=0

30 SEC

NOTIFY USER OF

CTSTMR =0

{

STREAMING

STATION

CTS=0ON

CTS TIMR=0

CD = OFF
A

NOTIFY USER

RTS=0FF

OF CTS FAILURE

RTS = ON

SHUT DOWN

CTS TIMER 20ms
TRANSMIT

CTS=0FF

CTS TMR=0

CTS=OFF

;

CTS=OFF

END OF TRANS

FDX

HDX

CTS TIMR <—

10 SEC

‘

CLEAR RTS

TIMR=0

CTS=ON
CANCEL CTS TiIMR

NOTIFY USER OF

CTS FAILURE

[

‘ SHUT DOWN ’
NOTES:

[3.1) CWTIMR -- CARRIER WAIT TIMER. IT DETECTS THE CONDITION WHERE THE LINK WAS NOT RELINQUISHED IN
TIME BY THE REMOTE END.

[3.2)CTSTMR -- CLEAR TO SEND TIMER. TIME CLEAR TO SEND GOING AWAY WHEN DROPPING RTS BECAUSE OF LINE
ERRORS. FALL-OUT COVERS CONDITION OF CONSTANT CTS MODEMS.
[3.3]IN FULL DUPLEX MODE -- DMP11 ASSERTS RTS CONSTANTLY. RTS IS DROPPED ONLY WHEN THERE ARE LINE
ERRORS.

[3.4) SOFTWARE INTERLOCK - CONDITION IS SWITCH SELECTABLE FOR CONSTANT CTS MODEMS.
MK.2706

Figure D-3

Modem Control (Transmit)
D-6

< TRANSMIT 2 )

'
LESS THAN 24 REQUEST

REMOTE PROGRAM LOAD

LOAD MESSAGES SENT

MESSAGES SENT

[ TiIMER=3 sec
|
L

y
24 REQUEST REMOTE PROGRAM

cLearpTR
|

]

| TIMER=-10 sEC|

TIMER=0

!
( TRANSMIT )

TIMER =0

seTotR

MK-2703

Figure D-4

Modem Control (Transmit 2)

D-7

( RECEIVE )

v
FULL-DUPLEX

HALF-DUPLEX

Y
TRANSMITTER NOT
ACTIVE

IN HALF DUPLEX, LINE UNIT 1
PROVIDES INTERLOCK TO
ENABLE RCV CLOCK ONLY IF

TRANSMITTER IS IDLE.
(RTS =OFF)

{

CD=ON

SYNC'ED ON NEW
FRAME

START TO RECE!VEJ—l
CD DROPPED IN THE
MIDDLE OF DATA

‘
CD = OFF
&

STREAM

RESET CDTIMR

TO 1.28 SEC

CD=ON

'
Y

COTIMR =0

NOTIFY USER OF
CARRIER LOSS
(CONTROL RESPONSE)

END OF

RECEIVE

[ RESET RECEN?RJ

MK-2704

Figure D-5

Mo dem Control (Receive)

( MOD STAT )

READ MODEM

WRITE MODEM

[6.1] STATUS

STATUS

(6.1]

READABLE MODEM SIGNALS:

CARRIER

[6.2]

WRITEABLE MODEM SIGNALS:
DATA TERMINAL READY

CLEAR TO SEND
MODEM READY (DSR)
HALF DUPLEX
REQUEST TO SEND

DATA TERMINAL READY
RING
TEST MODE
MK.2702

Figure D-6

Modem Control (Modem Status)

C CAL;MR )
| START 65 SEC CALL TIMERJ

CALL TIMER =0

VALID MESSAGE
RECEIVED FOR
THIS STATION

rCLEAF: TR

SET CALTMR

RESET RECEIVER

= OFF

AND

TRANSMITTER

[ TIMER=+-10 SEC|

TIMER =0

seTotr

]

NOTE: CALTMR = ON

MK-1967

Figure D-7

Modem Control (Call Timer)

(sHuT Down)

CLEAR DTR
AND RTS

RESET RECEIVER
AND TRANSMITTER

BOOTING

REMOTE LOAD

CALL TIMR=ON

DETECT

TIMR<«—10 SEC

TIMR=0

SET DTR

[

®
MK-26858

Figure D-8

Modem Control (Shutdown)

D-11

APPENDIX E

QMA DMV11
OPTION CONFIGURATIONS

E.1

INTRODUCTION

This appendix lists the option variations and cabinet kits available for the QMA DMV11 Synchronous
Controller module. The method for assigning DMV11 option designations is also described.

The communications option designations enable DIGITAL customers to obtain communication options
that are custom-tailored to their particular needs. FCC regulations require that all system cabinets
manufactured after October 1, 1983, and intended for use in the United States, be designed to limit
electromagnetic interference (EMI). Since both shielded and unshielded cabinets exist in the field, Digital
Equipment Corporation provides separate communication options for each cabinet type.

E.2 OPTION DESIGNATION CONVERSION
Since former DMV11 configurations are discontinued or changed to MAINTENANCE ONLY status,
the new option designations must be used to obtain the necessary equipment. Table E-1 can be used to

determine which communication option designations to use when designing or expanding upon a computer
system.

Communication options may be obtained by customers either at the time a system is purchased or as an
upgrade to an existing system in the field.

E.2.1
Installed Option
An add-on option is identified by two option designations: a base option designation and a cabinet kit

designation. When these designations are specified (see Table E-1), the appropriate module(s), cable(s),
and distribution panels are installed in the particular system being constructed.
E.2.2 Add-On Option
An add-on option is identified by the same method as the installed option (see Table E-1).
E.2.2.1
Base Options - The base option designation specifies the electronic module(s) and option
documentation.
E.2.2.2 Cabinet Kits — The cabinet kit designation specifies the internal cable, the distribution panel, and
an adaptor bracket for installing the distribution panel in a non-FCC compliant cabinet may be included.

External cables needed to connect to a modem or other external device are usually not included.

E.3 OPTION CONFIGURATION SUMMARY
Communication option designations ensure that the proper cable(s), distribution panels, and adaptor
brackets (if necessary) are shipped with each base option.

E-1

Table E-1

Option Compatibility Cross-Reference

OLD OPTION

DMVI11-AA

EQUIVALENT NEW OPTION

Base Option

Cabinet Kit

DMVI1I-M

CK-DMVI11-A(*)

DMVI11-M

CK-DMV11-F(*)

DMV11-M

CK-DMV11-B(*)

DMVI11-N

CK-DMV11-C(*)

(RS-232-C)

DMVI1-AA
(RS-423-A/449)

DMVI11-AB
(V.35)

DMV1I1-AC
(Integral Modem)

NOTE

The last character of the cabinet kit (*) varies
depending on which kit is required (refer to
Table E-3).

Communication options may be obtained by customers either at the time a system is purchased (a factoryinstalled system option) or as an upgrade to an existing system in the field (a field upgrade).
The basic designations refer to:

e
e

Base options
(Cabinet kits

Base options and cabinet kits can be factory installed or ordered as upgrades to systems already existing in
the field. A base option and cabinet kit together make a complete field upgrade option (that is; a base
option designation and cabinet kit designation must both be specified to obtain a complete field upgrade).
NOTE
A field upgrade option alone does not make an
unshielded cabinet FCC compliant. Shielded cabinets
are specially constructed to limit EMI.

E-2

E.3.1
Base Option Designations
Base option designations provide the following information

(Figure E-1):

DMV11-M

THE DEVICE NAME (THAT IS, DMV11) *—1 T
SPECIFIES A BASE OPTION (TABLE E-2)

Figure E-1

Table E-2

Base Option Designation

Electrical and Mechanical Interface Type

Character

Interface Type

RS-232-C (with full modem control)

C
F
M, N

V.35

Integral modem
RS-423-A /449
Base option

E.3.2 Cabinet Kit Designations
Cabinet kits enable customers to custom-tailor communicatio
lengths, distribution panels, and method of installation

n options to their particular cabinet. Cable
may vary depending on the cabinet kit obtained.

Cabinet kits are individually tailored to specific cabinet
cation options in both shielded (FCC compliant) and

types. This enables customers to install communiunshielded (non-FCC compliant) cabinets.

Cabinet kits include:
¢

Internal cable(s).

Distribution panel.

An adaptor bracket (if necessary).

The internal cable connects the module to the distribu

tion panel which is installed in an 1/0O bulkhead.
Typically, external cables needed to connect to a modem
or other external device are not supplied with the
option and must be ordered separately.

Cabinet kit designations have two characters following the device name (Figure E-2).
CK-DMV11-FA

SPECIFIES CABINET KIT I

THE DEVICE NAME (THAT IS, DMV11)
THE INTERFACE TYPE IDENTIFIER (TABLE E-2)
THE CABINET IDENTIFIER * (TABLE E-3)

*THE CABINET IDENTIFIER INDICATES WHICH CABLE
LENGTHS ARE SUPPLIED WITH THE CABINET KIT.
TK-11342

Cabinet
Identifier

Figure E-2

Cabinet Kit Designation

Table E-3

Cabinet Kit Components

Component Parts Supplied

Letters Indicate
Shielded Cabinets

A 53.34 cm (21 in) internal cable (see Note 1)
A distribution panel (PDP-11/23S) (see Note 2)

°
°

A 30.48 cm (12 in) internal cable (see Note 1)
A distribution panel (Micro-11) (see Note 2)

°
°

A 76.20 cm (30 in) internal cable (see Note 1)
A distribution panel (PDP-11/23+) (see Note 2)

A 91.44 cm (36 in) internal cable (see Note 1)

A 3.05 m (10 ft) internal cable/panel (see Note 1)

A 7.62 m (25 ft) interconnection cable

A distribution panel (VAX-11/725, PDP-11/84) (see Note 2)

Numbers Indicate
Unshielded Cabinets

NOTE

Integral modem versions use 70-18250/

RS-232-C version uses 70-20863 panel;

70-20862 cable/panel; V.35 versions use 7020861 cable/panel; all others use BCO8S cable.
RS-423-A/449 version uses 70-20864 panel

E-4

E.4
DMVI11 OPTION CONFIGURATIONS
Table E-4 provides a reference to other option configurations that are available
nous Controller beginning October 1, 1983.

Table E-4

for the DMV11 Synchro-

DMV11 Option Configurations

DMV11-M (BASE
OPTION USED IN
THE FOLLOWING

CABINET KITS

RS-232-C APPLICATIONS
¢

CK-DMV11-AA

CK-DMV11-AB

CK-DMV11-AC

CK-DMV11-A2

CK-DMV11-AF

1
1

RS-423/RS-449

APPLICATIONS
o

CK-DMV11-FA

CK-DMV11-FB

o«

CK-DMV11-FC

CK-DMV11-F3

CK-DMV11-FF

1
1

V.35 APPLICATIONS
« CK-DMV11-BA
+

CK-DMV11-BB

CK-DMV11-BC

CK-DMV11-B3

CK-DMV11-BF

1
1

DMV11-N (BASE OPTION

USED IN THE FOLLOW
ING CABINET KITS)

INTEGRAL MODEM

APPLICATIONS

CK-DMV11-CA

CK-DMV11-CB

1
1

o« CK-DMV11-CC
e

CK-DMV11-C3

CK-DMV11-CF

1
1

1
1
MKV86-1684

E-5

DMV11 Option Configurations (Cont)

Table E-4

DMV11-M (BASE
OPTION USED IN

THE FOLLOWING

CABINET KITS)

RS-232-C APPLICATIONS
e CK-DMV11-AA

o CK-DMV11-AB

e CK-DMV11-AC

e CK-DMV11-A2
»

CK-DMV11-AF

RS-423/RS-449
APPLICATIONS

e CK-DMV11-FA

« CK-DMV11-FB

» CK-DMV11-FC

e CK-DMV11-F3
o CK-DMV11-FF

V.35 APPLICATIONS

o CK-DMV11-BA

+ CK-DMV11-BB

« CK-DMV11-BC

« CK-DMV11-B3

¢ CK-DMV11-BF

DMV11-N (BASEOPTION
USED IN THE FOLLOW-

ING CABINET KITS)

INTEGRAL MODEM
APPLICATIONS

e CK-DMV11-CA

141

e CK-DMV11-CB

e CK-DMV11-CC

111

"o CK-DMV11-C3
o CK-DMV11-CF

1
1

111
Tt
MKV86-0884

E-6

Digital Equipment Corporation.Bedford, MA 01730