Digital PDFs

EK-350EA-UG-A01

November 1992

46 pages

Original

0.3MB

Document:	BA350-EA Modular Storage Shelf User's Guide
Order Number:	EK-350EA-UG
Revision:	A01
Pages:	46
Original Filename:

OCR Text

BA350–EA
Modular Storage Shelf
User’s Guide
Order Number: EK–350EA–UG. A01
This manual describes the BA350–SA modular storage shelf and the
rules for configuring the shelf to include power, system building blocks
(SBBs), device addressing, and SCSI buses. Procedures for determining
shelf status and replacing blowers are also included.

Digital Equipment Corporation
Maynard, Massachusetts

First Edition: November 1992
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.
The software described in this document is furnished under a license and may be used or copied
only in accordance with the terms of such license.
No responsibility is assumed for the use or reliability of software on equipment that is not supplied
by Digital Equipment Corporation or its affiliated companies.
Restricted Rights: Use, duplication, or disclosure by the U.S. Government is subject to restrictions
as set forth in subparagraph (c) (1) (ii) of the Rights in Technical Data and Computer Software
clause at DFARS 252.227-7013.
Copyright © Digital Equipment Corporation 1992
Printed in U.S.A.
All Rights Reserved.
The postpaid READER’S COMMENTS card requests the user’s critical evaluation to assist in
preparing future documentation.
FCC NOTICE: The equipment described in this manual 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 Subpart J 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.
AXP, DEC, DEC 10000, MicroVAX, RZ, VAXserver, and the DIGITAL logo are trademarks of Digital
Equipment Corporation.

This document was prepared using VAX DOCUMENT, Version 2.0.

Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1 Introducing the BA350–EA Modular Storage Shelf
1.1
1.2
1.3
1.4
1.4.1
1.4.2
1.5
1.6

BA350–EA Shelf Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HSx-Series Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shelf Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Supply LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SHELF_OK Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing SBBs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing Blowers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1–1
1–3
1–4
1–4
1–4
1–6
1–6
1–7

2 Configuring the BA350–EA Shelf
2.1
2.2
2.3
2.4

Power Configuration Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SBB Configuration Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SBB Device Addressing Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring a BA350–EA DECstor/me Modular Storage Shelf . . . . . . . . . .

2–1
2–1
2–2
2–4

3 BA350–EA Shelf SCSI Buses
3.1
3.2
3.3
3.4
3.5
3.6
3.7

SCSI Bus Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x1 SCSI Bus—Factory Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x2 SCSI Bus—Factory Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x3 SCSI Bus—Factory Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x4 SCSI Bus—Factory Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x5 SCSI Bus—Factory Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x6 SCSI Bus—Factory Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3–3
3–4
3–6
3–8
3–10
3–12
3–14

4 DWZZA–VA Bus Adapter
4.1
4.1.1
4.1.2
4.1.3
4.1.4
4.2
4.3

Major Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Device ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SCSI Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Terminating the SCSI Buses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Terminator Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly of the DWZZA–VA Bus Adapter . . . . . . . . . . . . . . . . . . . . . . .
Functional Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4–1
4–2
4–2
4–2
4–3
4–4
4–5

iii

Index
Figures
1–1
1–2
1–3
1–4
1–5
2–1
2–2
3–1
3–2
3–3
3–4
3–5
3–6
4–1
4–2

BA350–EA Shelf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Supply LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SHELF_OK Signal Jumper W1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing an SBB from the Shelf . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing Blowers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SBB Device Address Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BA350–EA Shelf—Front View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x1 Bus Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x2 Bus Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x3 Bus Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x4 Bus Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x5 Bus Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x6 Bus Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BA350–EA Shelf with DWZZA–VA Bus Adapter SBB Installed . . . . . .
Typical 3½-Inch SBB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1–2
1–5
1–6
1–7
1–9
2–3
2–4
3–5
3–7
3–9
3–11
3–13
3–15
4–1
4–4

BA350 DECstor/me Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DECstor/me SBB Address Switch Settings . . . . . . . . . . . . . . . . . . . . .
Configuring SCSI Buses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x1 SCSI Bus Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x2 SCSI Bus Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x3 SCSI Bus Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x4 SCSI Bus Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x5 SCSI Bus Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5x6 SCSI Bus Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SCSI Cable Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DWZZA–VA Bus Adapter Functional Specifications . . . . . . . . . . . . . . .

1–3
2–3
3–2
3–4
3–6
3–8
3–10
3–12
3–14
4–2
4–5

Tables
1–1
2–1
3–1
3–2
3–3
3–4
3–5
3–6
3–7
4–1
4–2

Preface
The BA350–EA Modular Storage Shelf User’s Guide describes how to configure
the BA350–EA shelf, and install and replace DECstor/me components.
Note
Shelf installation procedures are cabinet specific and are not included in
this manual.

Intended Audience
This manual is intended for use by personnel responsible for configuring, using,
and installing BA350 DECstor/me modular storage shelf systems.

Structure
This manual is organized as follows:
Chapter 1

Provides a description of the BA350–EA modular storage shelf
including components, status signals, and replacement procedures.

Chapter 2

Provides shelf-specific configuration rules for power, storage SBBs,
shelves, and device addressing.

Chapter 3

Provides a detailed description of shelf-specific SCSI buses including
terminators, jumpers, and devices by bus and location.

Chapter 4

Provides a description of the DWZZA–VA bus adapter used for
compatibility between 8-bit differential SCSI buses and 8-bit singleended SCSI buses.

Related Documents
The following table lists documents (alphabetically by title) that contain
information related to this product:
Document Title

Order Number

BA350 Modular Storage Shelf SBB User’s Guide

EK–SBB35–UG

BA350 Modular Storage Shelf Subsystem Configuration Guide

EK–BA350–CG

BA350 Modular Storage Shelf Subsystem User’s Guide

EK–BA350–UG

BA350–LA Modular Storage Shelf User’s Guide

EK–350LA–UG

BA350–SA Modular Storage Shelf User’s Guide

EK–350SA–UG

BA35X–VA Vertical Mounting Kit User’s Guide

EK–350SV–UG

BA655 SCSI Disk and Tape PIU Installation Guide

EK–BA655–IN

Installation Notice—RZ73 Bus Termination and Jumper
Installation Guide

EK–RZ73X–IS

MicroVAX/VAXserver 3100 and DECsystem 5100 RZ25
Installation Guide Addendum

EK–RZ2MV–AD

RZ Series Disk Drive Reference Manual

EK–RZXXD–RM

RZ22, RZ23, RZ24 Disk Drive Subsystem Service Manual

EK–RZ234–SV

RZ24 Hard Disk Drive Installation Guide

EK–RZ24I–IS

RZ25–S Mounting Bolt/Bracket Installation Instructions

EK–RZ25S–IN

RZ2x Hard Disk Drive Upgrade Installation Instructions

EK–RZ2XH–UG

RZ2x Series Drive Bracket Installation Sheet

EK–RZ2XD–UG

TLZ06 Cassette Tape Drive Installation Guide

EK–STEXP–AD

TLZ06 Cassette Tape Drive Owner’s Manual

EK–TLZ06–OM

Documentation Conventions
The following conventions are used in this manual:

boldface type

Boldface type indicates the first instance of terms being defined in text,
in the glossary, or both.

italic type

Italic type indicates emphasis and complete manual titles. In the
glossary, italic type is also used to indicate cross-references.

1
Introducing the BA350–EA Modular Storage
Shelf
This manual describes the BA350–EA modular storage shelf including
configuration rules, system building blocks (SBBs)†, shelf status, power, blowers,
and SCSI buses.

1.1 BA350–EA Shelf Description
The BA350–EA shelf is a basic entry subsystem that can be expanded to
accommodate two HSx-series controllers, six system building blocks (SBBs), and
an adapter.
Note
The mounting brackets required and the procedures for installing
this shelf are unique to each cabinet type and are described in the
cabinet-specific user’s guide.

The BA350–EA shelf is basically a double-height shelf with a common backplane
and requires twice the vertical clearance of a standard, single-height shelf.
The BA350–EA shelf can be installed horizontally or vertically in a storage array,
in a data center cabinet, or in a BA35X–VA vertical mounting kit (stand).
The dimensions of the BA350–EA shelf are as follows:
Height—300 millimeters (11.8 inches)
Width—445 millimeters (17.5 inches)
Depth—350 millimeters (13.8 inches)
Weight—22.7 kilograms (50.0 pounds)

† SBBs are devices installed in either a 3½-inch or 5¼-inch modular carrier, including
disk drives, tape drives, CDROMs, static storage devices, power supplies, adapters,
CPUs, and so on.

Introducing the BA350–EA Modular Storage Shelf 1–1

Introducing the BA350–EA Modular Storage Shelf
1.1 BA350–EA Shelf Description
As shown in Figure 1–1, the upper half of the BA350–EA shelf is for controller
devices and the lower half is for storage devices.
Figure 1–1 BA350–EA Shelf

POWER
(7)
T

(6)

1
T

3
T

4
T

5
T

6
T

POWER
(7)

0 (6) 5

CXO-3588A-MC

The BA350–EA modular storage shelf differs from other DECstor/me storage
shelves in that:
•

The SCSI address and the slot number are not always the same.
The slot numbers are shown in parentheses when:
The slot number and the SCSI address are not the same.
The slot does not have a SCSI address.

•

Both slot 0 and slot 6 of the storage device section of the BA350–EA have a
SCSI address of 0.

•

The BA350–EA shelf requires a power supply in each section (controller and
storage).

•

The controller section of the BA350–EA shelf can accommodate two power
supplies and two HSx-series controllers. The positions for the HSx-series
controllers are software dependent.
The storage device section of the BA350–EA shelf can contain a maximum of
one adapter, one power supply, and six 3½-inch SBBs.

•

The primary power supplies are always installed in slot 7 in both the
controller and the storage sections of the BA350–EA shelf. The primary
power supply type is determined by the cabinet power distribution unit.

•

An optional, redundant power supply or a battery backup unit (BBU) can be
installed in slot 6 when fewer than six SBBs are already installed.
Note
Installing a redundant power supply or BBU in the storage device section
of the BA350–EA shelf reduces the number of 3½-inch storage devices
that can be installed to five.

•

There are six single-ended SCSI bus connectors located at the bottom of the
controller section of the shelf.

1–2 Introducing the BA350–EA Modular Storage Shelf

Introducing the BA350–EA Modular Storage Shelf
1.1 BA350–EA Shelf Description
Table 1–1 lists the DECstor/me products required for different configurations,
based on the number of 3½-inch devices on each of the five SCSI buses. The rules
used for developing this table are as follows:
•

The BA350–EA modular storage shelf can support a maximum of one device
per bus. To increase the number of devices per bus requires adding BA350–
SA storage shelves.

•

The primary power supply can be either of the following, based on the type of
cabinet power system:
–

BA350–HA universal ac input power supply

–

BA350–HB universal dc input power supply

Table 1–1 BA350 DECstor/me Products
Devices per SCSI Bus
Item

BA350–SA shelf
Primary power supply
3½-inch SBB
BA35X-MB SCSI terminator board†
BA35X–MC SCSI jumper board†
Mounting bracket kit‡

0
2
5
6
0
1

1
3
10
5
2
2

2
4
15
4
2
3

4
6
20
6
7
5

4
6
25
6
8
5

4
6
30
6
8
5

†One terminator per bus; one jumper per unterminated, extended bus.
‡Not required for BA35X–VA vertical mounting kit. See cabinet user’s guide for option number.

Note
The configuration rules in the following sections have precedence over
those listed in BA350 Modular Storage Shelf Subsystem User’s Guide.

1.2 HSx-Series Controllers
HSx-series controllers can be installed in either the first or third slot. The actual
location is software dependent. Refer to the specific controller documentation to
determine if the controller can be removed and replaced without removing power
from the shelf (hot swap method). See Section 1.5 for more information on hot,
cold, and warm swap methods.
Whenever the controller is changed, it must be reconfigured, and the software
reloaded and retested as described in the specific controller user’s guide.

Introducing the BA350–EA Modular Storage Shelf 1–3

Introducing the BA350–EA Modular Storage Shelf
1.3 Adapters

1.3 Adapters
A 16-bit differential SCSI system cannot be connected directly to a single-ended,
8-bit SCSI system. However, with the proper adapter, a differential SCSI system
operating in the 8-bit mode is compatible with a single-ended SCSI bus. The
BA350 modular storage shelf subsystem uses the DWZZA–VA bus adapter for
compatibility between these two SCSI bus types.
See Chapter 4 for a complete description of and the specifications for the DWZZA
adapter.

1.4 Shelf Status
Two conditions are monitored for the shelf: cooling and power. The cabinet
provides the cooling and the shelf power supply provides the +5 Vdc and +12
Vdc of power to operate the SBBs. When there is an overtemperature condition
or a power supply failure, the status is reported to the host or controller and
is indicated to the user by the illumination of one or both of the power supply
LEDs.

1.4.1 Power Supply LEDs
The power supply is shown in Figure 1–2. There are two status LEDs on the
front of the power supply:
•

The upper LED indicates the shelf status.

•

The lower LED indicates the power supply status.

Depending on whether or not either or both of the LEDs are lit indicates one of
the following conditions:
•

When the shelf status (upper) LED is on and the power supply status (lower)
LED is on, the temperature is within the proper operating range and the
power supplies are functioning properly.

•

When the shelf status (upper) LED is off and the power supply status (lower)
LED is on, there is an overtemperature condition.

•

When both the shelf status (upper) LED and the power supply status (lower)
LED are off, either the power supply has failed or the input voltage is
incorrect.

1–4 Introducing the BA350–EA Modular Storage Shelf

Introducing the BA350–EA Modular Storage Shelf
1.4 Shelf Status
Figure 1–2 Power Supply LEDs

SHELF
STATUS LED

POWER SUPPLY
STATUS LED

CXO-3613A-PH

Introducing the BA350–EA Modular Storage Shelf 1–5

Introducing the BA350–EA Modular Storage Shelf
1.4 Shelf Status
1.4.2 SHELF_OK Signal
The shelf status (SHELF_OK) is reported to the host or controller that can
process this information. However, since not all hosts and controllers can process
this signal, this signal is sent to a compatible host or controller by installing
jumper W1 on both the terminator board (BA35X–MB) and the jumper board
(BA35X–MC) on each shelf, as shown in Figure 1–3. The terminator board, the
jumper board, and jumper W1 are installed prior to shipment.
When the SHELF_OK signal is not used, install jumper W1 on the two ground
pins shown in Figure 1–3.
Figure 1–3 SHELF_OK Signal Jumper W1

W1
W1
GROUND
PINS
GROUND
PINS

TERMINATOR

JUMPER
CXO-3636A-MC

1.5 Replacing SBBs
There are three methods for replacing SBBs, including power supplies—hot swap,
warm swap, and cold swap. A full description of these methods is contained in
the BA350 Modular Storage Shelf Subsystem User’s Guide.
CAUTION
To prevent electrostatic discharge (ESD) damage to an SBB, do not touch
the SBB connector.

You use the LEDs on the front of the SBB to determine which SBBs are
operational and which have failed.
•

For power supplies, use the hot swap method only when there are two power
supplies in a shelf. You can remove the failed power supply while the other
furnishes the power.

1–6 Introducing the BA350–EA Modular Storage Shelf

Introducing the BA350–EA Modular Storage Shelf
1.5 Replacing SBBs
CAUTION
When removing or replacing an SBB, always use both hands to support
the weight of the SBB.
For storage SBBs, you can use the hot swap method provided that the green
status LED is off, indicating the unit is not being accessed.
•

Use the warm swap method when there are multiple shelves in a cabinet and
it is necessary to remove power from a particular shelf because the power
supply has failed. When this is the case, none of the devices on that shelf are
operational until the replacement supply is installed.

•

Use the cold swap method when input power is removed from all shelves in a
cabinet by turning off the power at the power controller. This normally only
occurs during initial installation. None of the shelves are operational until
the input power is restored.

To remove or replace an SBB, use the following procedure:
Step

Procedure

Press the two mounting tabs (as shown in Figure 1–4) to release the SBB and pull
the SBB out of the shelf.

Insert the replacement SBB into the guide slots and push it in until the tabs lock
in place.

Figure 1–4 Removing an SBB from the Shelf

CXO-3611A-PH

1.6 Replacing Blowers
Each BA350–SA shelf has two blowers mounted on the rear of the shelf.
Connectors on the backplane provide the +12 Vdc of power to operate the blowers.
As long as one blower is operational on each shelf, there is sufficient air flow to
prevent an overtemperature condition. When either blower fails, the shelf status
(upper) LED on the power SBB lights and an error message is passed to the
controller or host.

Introducing the BA350–EA Modular Storage Shelf 1–7

Introducing the BA350–EA Modular Storage Shelf
1.6 Replacing Blowers
WARNING
Service procedures described in this manual that involve blower removal
or access to the rear of the shelf must be performed only by qualified
service personnel.
To reduce the risk of electrical energy hazard, disconnect the power cables
from the shelf power SBBs before removing shelf blower assemblies or
performing service in the backplane area, such as modifying the SCSI
bus.

When a blower is removed, the change in the air flow pattern reduces the cooling
to the point that the shelf can overheat within 60 seconds.
To replace a blower, use the following procedure:
Note
Replacing a blower requires access to the rear of the shelf. If the rear of
the shelf is not accessible, turn off the power, remove the shelf from the
cabinet, and perform steps 1 through 6. Then replace the shelf in the
cabinet and apply power.

Step

Procedure

Disconnect all power cables to shelf power SBBs.

Use a Phillips screwdriver to remove the safety screw in the upper right corner or
lower left corner of the blower.

As shown in Figure 1–5, press the upper and lower blower mounting tabs in to
release the blower.

Pull the blower straight out to disconnect it from the shelf power connector.

Align the replacement blower connector and push the blower straight in, making
sure that both mounting tabs lock in place.

Replace the safety screw.

Connect the shelf power cables and verify that the shelf and all SBBs are operating
properly.

1–8 Introducing the BA350–EA Modular Storage Shelf

Introducing the BA350–EA Modular Storage Shelf
1.6 Replacing Blowers
Figure 1–5 Replacing Blowers

CXO-3515A-PH

Introducing the BA350–EA Modular Storage Shelf 1–9

2
Configuring the BA350–EA Shelf
This chapter describes the rules for configuring a BA350–EA modular storage
shelf including power, system building blocks (SBBs), and device addresses.
Note
The configuration rules in the following sections have precedence over
those listed in the BA350 Modular Storage Shelf Subsystem User’s Guide.

2.1 Power Configuration Rules
Use the following rules to configure the power for a BA350–EA modular storage
shelf:
•

Each BA350–EA shelf requires either an ac or dc primary power supply,
based upon the cabinet power distribution unit.

•

The primary power supply is installed in slot 7 (power slot).

•

When slot 6 does not contain a storage SBB, either of the following can be
installed:
–

An optional redundant power supply

–

An optional battery backup unit (BBU)

2.2 SBB Configuration Rules
Use the following rules to configure the SBBs (disk drives, tape drives, and so
forth) in the BA350–EA shelf:
•

The Digital storage devices available for use in the BA350–EA shelf are listed
in BA350 Modular Storage Shelf Subsystem Configuration Guide.

•

The maximum number of SBBs you can install in a BA350–EA modular
storage shelf is determined by:
— The SBB physical size (either 3½-inch or 5¼-inch)
— The bus configuration

•

Software control signals on the SCSI bus are required to ensure that the disk
drives on each shelf spin up sequentially.
CAUTION
To prevent electrostatic discharge (ESD) damage to an SBB, do not touch
the SBB connector.

Configuring the BA350–EA Shelf 2–1

Configuring the BA350–EA Shelf
2.3 SBB Device Addressing Rules

2.3 SBB Device Addressing Rules
Use the following rules to assign device addresses to the SBBs (disk drives, tape
drives, and so forth) in a DECstor/me shelf:
CAUTION
Each device address on a SCSI bus or DECstor/me storage shelf can only
be used once.

•

The maximum number of device addresses per SCSI bus or DECstor/me
modular storage shelf is seven.

•

The SBB device address is determined automatically by its physical location
in the shelf unless the SBB has a device address switch.
Note
Unless specifically stated otherwise, DECstor/me modular storage shelf
slot numbers and SCSI addresses are the same.

•

The 3½-inch tape drive SBBs and all 5¼-inch SBBs have a six-bit address
switch located on the rear of the SBB as shown in Figure 2–1. With this
switch, you can select a SCSI address in the range 0 through 7. Table 2–1
lists the valid device address switch positions.

•

Setting the switch to automatic, as described in Table 2–1, enables the
automatic addressing mode, which uses the physical position of the SBB to
determine the address.

•

When there is no address switch or you set the switch to automatic, the SBB
connector position determines the SCSI device address. For example:
–

If the SBB connector is in slot 5, the device address is 5.

–

If the SBB connector is in slot 3, the device address is 3.

•

The address switch for a 5¼-inch, full-height (FH) SBB is installed adjacent
to the center SBB connector.

•

The address switch for the lower 5¼-inch, half-height (HH) SBB is installed
adjacent to the center SBB connector.

•

The address switch for the upper 5¼-inch, HH SBB is installed adjacent to
the left SBB connector.

2–2 Configuring the BA350–EA Shelf

Configuring the BA350–EA Shelf
2.3 SBB Device Addressing Rules
Table 2–1 DECstor/me SBB Address Switch Settings
SCSI Switch Number
SCSI address 0
SCSI address 1
SCSI address 2
SCSI address 3
SCSI address 4
SCSI address 5
SCSI address 6
SCSI address 71
Automatic
1

Off
On
Off
On
Off
On
Off
On
Off

Off
Off
On
On
Off
Off
On
On
Off

Off
Off
Off
Off
On
On
On
On
Off

Off
Off
Off
Off
Off
Off
Off
Off
On

SCSI address 7 is generally reserved for the host.

Figure 2–1 SBB Device Address Switch
5 1/4" SBB

3 1/2" SBB

ICE

(B)

VIC

A)
SWITCH A
SWITCH B

1
2
3
4
5
6

DEVICE
ADDRESS
SWITCH

OFF ON
CXO-3630A-MC

Configuring the BA350–EA Shelf 2–3

Configuring the BA350–EA Shelf
2.4 Configuring a BA350–EA DECstor/me Modular Storage Shelf

2.4 Configuring a BA350–EA DECstor/me Modular Storage Shelf
The BA350–EA modular storage shelf shown in Figure 2–2 differs from other
DECstor/me shelves in that:
•

The SBB slot number and the SCSI device address are not always the same.

•

Two slots have SCSI device address 0: slot 0 and slot 6.
CAUTION
SCSI device address 0 is assigned to both slot 0 and slot 6. Do not install
storage SBBs in slot 0 and slot 6 at the same time.

•

The SCSI address and the slot number are not the same for all slots. When
there is a difference between the slot number and the SCSI address, or there
is no SCSI address, the slot number is shown in parentheses.

Figure 2–2 BA350–EA Shelf—Front View

POWER
(7)
T

(6)

1
T

3
T

4
T

5
T

6
T

POWER
(7)

0 (6) 5

CXO-3588A-MC

•

Slot 0 is normally used for an adapter.

•

There are six terminators or jumper connectors on the rear of the backplane
behind storage shelf slots 1 through 5 and slot 7, the power slot, respectively.
Note
A terminator board (BA35X–MB) must be installed in the slot 1 connector
on the rear backplane for all configurations.

•

Each terminator and jumper board requires that jumper W1 be installed to
pass the SHELF_OK signal to compatible hosts and controllers.
Note
Read the specific controller documentation to determine if the controller
can process the SHELF_OK signal.

2–4 Configuring the BA350–EA Shelf

Configuring the BA350–EA Shelf
2.4 Configuring a BA350–EA DECstor/me Modular Storage Shelf
•

The primary power supply is installed in slot 7 on both the controller and
the storage shelf. Slot 6 on both shelves can be used for a redundant power
supply or a battery backup unit (BBU).

Configuring the BA350–EA Shelf 2–5

3
BA350–EA Shelf SCSI Buses
This chapter describes the factory SCSI bus configurations of the BA350–EA
and BA350–SA shelves when using an HSZ10–AX controller, including the
terminators, jumpers, and SBBs. The SCSI bus components (that is, jumpers,
terminators, and SBBs) and their physical locations are also defined.
Note
The SCSI bus factory configurations described in this chapter are only
valid when using the HSZ10–AX controller.

The BA350–EA has six single-ended SCSI bus connectors mounted at the
bottom of the controller shelf on the front of the backplane. The cables for these
connectors exit through the front of the shelf.
Each bus requires a terminator at both ends. Jumpers are required for extending
a bus. The terminator and jumper connectors are mounted on the rear of the
backplane. You must remove the blowers to configure the SCSI buses. The use of
the jumpers is determined by the number of drives installed. The basic HSZ10
5x1 bus does not require any jumpers. Jumpers are required for all the other bus
configurations (that is, 5x2 through 5x6). See Section 3.1 for more information on
SCSI bus configurations.
Note
Be sure to place unused jumpers where you can readily find them.
After you have configured and tested your buses, you can mount the extra
jumpers on unused backplane connectors without affecting bus operation.

WARNING
Service procedures described in this manual involving blower removal or
access to the rear of the shelf must be performed only by qualified service
personnel.
To reduce the risk of electrical energy hazard, disconnect the power cables
from the shelf power SBBs before removing shelf blower assemblies or
performing service in the backplane area, such as modifying the SCSI
bus.

BA350–EA Shelf SCSI Buses 3–1

BA350–EA Shelf SCSI Buses

To initially configure the buses, complete the following procedure:
Table 3–1 Configuring SCSI Buses
Step

Procedure

Select the bus configuration from Sections 3.2 through 3.7.

Turn off power to the shelves.

If you cannot access the rear of the shelf, remove the shelf from the cabinet.

Remove the blowers from the shelf as described in Section 1.6.

Ground yourself by pressing a finger to an open space on the backplane.

CAUTION
To prevent ESD damage to devices on the SCSI bus, do not touch the SBB
backplane connector pins.
6.

Install jumper W1 on all terminator boards (BA35X–MB) and jumper boards
(BA35X–MC) to either enable or disable the SHELF_OK signal. (Refer to
Section 1.4.2.)

Position terminators and jumpers as shown in Figures 3–1 through 3–6.

Position the storage devices as shown in Figures 3–1 through 3–6.

Repeat Steps 2 through 8 for all shelves.

10.

Replace the shelves that were removed in step 3.

11.

Apply power to all shelves and verify proper operation.

Note
The following diagrams show the SCSI bus address for each BA350
modular shelf slot. Normally, the device address and the slot number are
the same. When there is a difference or there is no device address, the
slot number is shown in parentheses.

Sections 3.2 through 3.7 define the BA350–EA shelf factory configurations when
using the HSZ10–AX controller. For each bus, there is a table that describes the
components required (for example, buses, SBBs, terminators, and so forth), the
buses for each shelf, and the location, by slot, of the terminators and jumpers.
There is also a schematic diagram showing the same information.

3–2 BA350–EA Shelf SCSI Buses

BA350–EA Shelf SCSI Buses
3.1 SCSI Bus Configurations

3.1 SCSI Bus Configurations
SCSI bus configurations are identified by a three-character descriptor which
defines:
•

The number of SCSI buses

•

The maximum number of SBBs (that is, devices or ranks allowable per bus)

This descriptor is also used to define the maximum number of SBBs per
configuration. For example, a 5x3 SCSI bus configuration indicates that there are
five SCSI buses and three SBBs per bus. This configuration can accommodate a
maximum of 15 SBBs.

BA350–EA Shelf SCSI Buses 3–3

BA350–EA Shelf SCSI Buses
3.2 5x1 SCSI Bus—Factory Configuration

3.2 5x1 SCSI Bus—Factory Configuration
The 5x1 SCSI bus configuration does not require any jumpers or internal SCSI
cables. Table 3–2 defines the 5x1 SCSI bus components and their physical
locations. Figure 3–1 is a schematic of this configuration.
Table 3–2 5x1 SCSI Bus Components
Item

BA350–EA

SCSI Buses: 5
SCSI bus 1
SCSI bus 2
SCSI bus 3
SCSI bus 4
SCSI bus 5
Terminators (BA35X–MB): 6
SCSI bus 1
SCSI bus 2
SCSI bus 3
SCSI bus 4
SCSI bus 5

Slot 1†
Slot 7
Slot 5
Slot 4
Slot 3
Slot 2

Jumpers (BA35X–MC): None

3½-Inch Storage SBBs: 5
SCSI bus 1
SCSI bus 2
SCSI bus 3
SCSI bus 4
SCSI bus 5

Slot 5
Slot 4
Slot 3
Slot 2
Slot 1

†Install this terminator for all configurations.

3–4 BA350–EA Shelf SCSI Buses

BA350–EA Shelf SCSI Buses
3.2 5x1 SCSI Bus—Factory Configuration
Figure 3–1 5x1 Bus Schematic

POWER
(7)
T

(6)

1
T

3
T

4
T

5
T

6
T

POWER
(7)

0 (6) 5

LEGEND
BACKPLANE CONNECTION
T

TERMINATOR

JUMPER
SCSI CABLE
CXO-3589A-MC

BA350–EA Shelf SCSI Buses 3–5

BA350–EA Shelf SCSI Buses
3.3 5x2 SCSI Bus—Factory Configuration

3.3 5x2 SCSI Bus—Factory Configuration
Table 3–3 defines the 5x2 SCSI bus components and their physical locations.
Figure 3–2 is a schematic of this configuration.
CAUTION
Do not use the following configuration when upgrading, as it can damage
SCSI devices.

Table 3–3 5x2 SCSI Bus Components
Item

BA350–EA

First
BA350–SA

SCSI Buses: 5
SCSI bus 1
SCSI bus 3
SCSI bus 5

SCSI bus 2
SCSI bus 4

Terminators (BA35X–MB): 5
Slot 1†
SCSI bus 1
Slot 7
SCSI bus 3
Slot 5
SCSI bus 5
Slot 3

SCSI bus 2
SCSI bus 4
Slot 5

Jumpers (BA35X–MC): 2
SCSI bus 3
Slot 4
SCSI bus 5
Slot 2
3½-Inch Storage SBBs: 10
SCSI bus 1
Slot 5
Slot 6
SCSI bus 3
Slot 3
Slot 4
SCSI bus 5
Slot 1
Slot 2

SCSI bus 2
Slot 2
Slot 4
SCSI bus 4
Slot 3
Slot 5

†Install this terminator for all configurations.

3–6 BA350–EA Shelf SCSI Buses

BA350–EA Shelf SCSI Buses
3.3 5x2 SCSI Bus—Factory Configuration
Figure 3–2 5x2 Bus Schematic

POWER
(7)
T

(6)

1
T

3
J

4
T

5
T

POWER
(7)

0 (6) 5

0
J

1
2
3
4

5
6
POWER (7)

LEGEND
BACKPLANE CONNECTION
T

TERMINATOR

JUMPER
SCSI CABLE
CXO-3590A-MC

BA350–EA Shelf SCSI Buses 3–7

BA350–EA Shelf SCSI Buses
3.4 5x3 SCSI Bus—Factory Configuration

3.4 5x3 SCSI Bus—Factory Configuration
Table 3–4 defines the 5x3 SCSI bus components and their physical locations.
Figure 3–3 is a schematic of this configuration.
CAUTION
Do not use the following configuration when upgrading, as it can damage
SCSI devices.

Table 3–4 5x3 SCSI Bus Components
Item

BA350–EA

First
BA350–SA

Second
BA350–SA

SCSI bus 1
SCSI bus 2

SCSI bus 3
SCSI bus 4

SCSI bus 1
SCSI bus 2
Slot 5

SCSI bus 3
SCSI bus 4
Slot 5

SCSI bus 1
Slot 0
Slot 2
Slot 4
SCSI bus 2
Slot 1
Slot 3
Slot 5

SCSI bus 3
Slot 0
Slot 2
Slot 4
SCSI bus 4
Slot 1
Slot 3
Slot 5

SCSI Buses: 5
SCSI bus 5

Terminators (BA35X–MB): 4
Slot 1†
SCSI bus 5
Slot 5

Jumpers (BA35X–MC): 2
SCSI bus 5
Slot 2
Slot 3
3½-Inch Storage SBBs: 15
SCSI bus 5
Slot 1
Slot 2
Slot 3

†Install this terminator for all configurations.

3–8 BA350–EA Shelf SCSI Buses

BA350–EA Shelf SCSI Buses
3.4 5x3 SCSI Bus—Factory Configuration
Figure 3–3 5x3 Bus Schematic

POWER
(6)

(7)
T

1
J

3
T

4
J

5
T

POWER
4

0 (6) 5

(7)

0
J

0
J
1

4
T

4
T
5

POWER (7)

LEGEND
BACKPLANE CONNECTION
T

TERMINATOR

JUMPER
SCSI CABLE
CXO-3591A-MC

BA350–EA Shelf SCSI Buses 3–9

BA350–EA Shelf SCSI Buses
3.5 5x4 SCSI Bus—Factory Configuration

3.5 5x4 SCSI Bus—Factory Configuration
Table 3–5 defines the 5x4 SCSI bus components and their physical locations.
Figure 3–4 is a schematic of this configuration.
CAUTION
Do not use the following configuration when upgrading, as it can damage
SCSI devices.

Table 3–5 5x4 SCSI Bus Components
Item

BA350–EA

First
BA350–SA

Second
BA350–SA

Third
BA350–SA

Fourth
BA350–SA

SCSI bus 5

SCSI bus 1

SCSI bus 2

SCSI bus 3

SCSI bus 4

Slot 1

Slot 5

Slot 2
Slot 3
Slot 4
Slot 5

SCSI Buses: 5

Terminators (BA35X–MB): 6
Slot 1†
Slot 5
Jumpers (BA35X–MC): 7
Slot 2
Slot 3
Slot 4
3½-Inch Storage SBBs: 20
Slot 1
Slot 2
Slot 3
Slot 4

†Install this terminator for all configurations.

3–10 BA350–EA Shelf SCSI Buses

BA350–EA Shelf SCSI Buses
3.5 5x4 SCSI Bus—Factory Configuration
Figure 3–4 5x4 Bus Schematic

POWER
(7)

(6)

1
T

3
J

4
J

5
T

POWER
(7)

0
T

4
J

POWER (7)

LEGEND
BACKPLANE CONNECTION
T

TERMINATOR

JUMPER
SCSI CABLE
CXO-3592A-MC

BA350–EA Shelf SCSI Buses 3–11

BA350–EA Shelf SCSI Buses
3.6 5x5 SCSI Bus—Factory Configuration

3.6 5x5 SCSI Bus—Factory Configuration
Table 3–6 defines the 5x5 SCSI bus components and their physical locations.
Figure 3–5 is a schematic of this configuration.
CAUTION
Do not use the following configuration when upgrading, as it can damage
SCSI devices.

Table 3–6 5x5 SCSI Bus Components
Item

BA350–EA

First
BA350–SA

Second
BA350–SA

Third
BA350–SA

Fourth
BA350–SA

SCSI bus 5

SCSI bus 1

SCSI bus 2

SCSI bus 3

SCSI bus 4

Slot 1

Slot 5

Slot 1
Slot 2
Slot 3
Slot 4
Slot 5

SCSI Buses: 5

Terminators (BA35X–MB): 6
Slot 1†
Slot 7
Jumpers (BA35X–MC): 8
Slot 2
Slot 3
Slot 4
Slot 5
3½-Inch Storage SBBs: 25
Slot 1
Slot 2
Slot 3
Slot 4
Slot 5

†Install this terminator for all configurations.

3–12 BA350–EA Shelf SCSI Buses

BA350–EA Shelf SCSI Buses
3.6 5x5 SCSI Bus—Factory Configuration
Figure 3–5 5x5 Bus Schematic

POWER
(7)
T

(6)

2
J

1
J

3
J

5
T

POWER

0
T

4
J

0 (6) 5

(7)

4
J

POWER (7)

LEGEND
BACKPLANE CONNECTION
T

TERMINATOR

JUMPER
SCSI CABLE
CXO-3593A-MC

BA350–EA Shelf SCSI Buses 3–13

BA350–EA Shelf SCSI Buses
3.7 5x6 SCSI Bus—Factory Configuration

3.7 5x6 SCSI Bus—Factory Configuration
Table 3–7 defines the 5x6 SCSI bus components and their physical locations.
Figure 3–6 is a schematic of this configuration.
CAUTION
Do not use the following configuration when upgrading, as it can damage
SCSI devices.

Table 3–7 5x6 SCSI Bus Components
Item

BA350–EA

First
BA350–SA

Second
BA350–SA

Third
BA350–SA

Fourth
BA350–SA

SCSI bus 5

SCSI bus 1

SCSI bus 2

SCSI bus 3

SCSI bus 4

Slot 1

Slot 5

Slot 0
Slot 1
Slot 2
Slot 3
Slot 4
Slot 5

SCSI Buses: 5

Terminators (BA35X–MB): 6
Slot 1†
Slot 7
Jumpers (BA35X–MC): 8
Slot 2
Slot 3
Slot 4
Slot 5
3½-Inch Storage SBBs: 30
Slot 1
Slot 2
Slot 3
Slot 4
Slot 5
Slot 6

†Install this terminator for all configurations.

3–14 BA350–EA Shelf SCSI Buses

BA350–EA Shelf SCSI Buses
3.7 5x6 SCSI Bus—Factory Configuration
Figure 3–6 5x6 Bus Schematic

POWER
(7)
T

(6)

1
J

3
J

4
J

5
T

POWER

0
T

4
J

0 (6) 5

(7)

4
J

POWER (7)

LEGEND
BACKPLANE CONNECTION
T

TERMINATOR

JUMPER
SCSI CABLE
CXO-3594A-MC

BA350–EA Shelf SCSI Buses 3–15

4
DWZZA–VA Bus Adapter
The DECstor/me modular storage shelf subsystem uses the DWZZA–VA bus
adapter for compatibility between the two SCSI bus types. The DWZZA–VA bus
adapter is mounted in a 3½-inch system building block (SBB). The DWZZA–VA
bus adapter can only be installed in slot 0 of a storage shelf, as shown in
Figure 4–1. The DWZZA–VA bus adapter is connected to the HSx controller with
a cable and to the host by the SCSI cable connected to SCSI connector 6.
Figure 4–1 BA350–EA Shelf with DWZZA–VA Bus Adapter SBB Installed
CONTROLLER 1
POWER

CONTROLLER 2

(7)
T

(6)

1
T

3
T

4
T

5
T

6
T

POWER

DWZZA-VA BUS ADAPTER SBB
BN21L-SERIES CABLE
0 (6) 5

(7)

TO SINGLE-ENDED
SCSI HOST CONNECTOR
(BN21H-SERIES CABLE)

LEGEND
BACKPLANE CONNECTION
T

TERMINATOR

JUMPER
SCSI CABLE
CXO-3637A-MC

The DWZZA–VA bus adapter is mounted in a standard 3½-inch SBB and is
always mounted in slot 0 of a DECstor/me shelf.

4.1 Major Features
The major features of the DWZZA–VA bus adapter are as follows:
•

No SCSI device modification is required.

•

The use of two DWZZA–VA bus adapters extends the effective length of a
synchronous, single-ended SCSI bus to 31 meters (102 feet).

•

Data transfers are supported at rates of up to 10 Megabytes/second.

•

A SCSI device address is not used.
DWZZA–VA Bus Adapter 4–1

DWZZA–VA Bus Adapter
4.1 Major Features
•

Two physical buses are converted into one logical bus with a total of eight
device addresses (0 through 7).

•

Both buses are terminated in the end-bus configuration.

•

Either bus can be terminated in the mid-bus configuration.

•

DWZZA–VA bus adapter operation is transparent to both buses.

•

SCSI–2 bus phases are supported.

4.1.1 Device ID
The DWZZA–VA bus adapter does not pass the SCSI shelf ID data to the
differential SCSI device. Therefore, no device conflict exists with shelf slot 0 and
SCSI hosts, which are manually set to SCSI ID 6 or 7.

4.1.2 SCSI Cables
The SCSI cables used with the DWZZA–VA bus adapter and the HSZ10–AX
controller are shown in Table 4–1.
Table 4–1 SCSI Cable Types
Cable Number

Connectors
Single-Ended Host to BA350-EA Shelf

BN21H

50-pin, high density, male, straight
50-pin, high density, male, right-angle, 2-56 jackscrews

BN21J

50-pin, high density, male, straight
50-pin, high density, male, straight
DWZZA–VA Bus Adapter to HSx Series Controller

BN21L

68-pin, high density, male, right-angle, 2-56 jackscrews
68-pin, high density, male, right-angle, 2-56 jackscrews

4.1.3 Terminating the SCSI Buses
All SCSI buses are terminated at the physical ends of the bus or cable. The
configuration shown in Figure 4-1 is terminated in the following manner:
•

•

The single-ended host is connected to the adapter using SCSI connector 6 on
the BA350–EA modular storage shelf. The procedures for terminating the
single-ended bus are:
–

Install a single-ended bus terminator on the host.

–

Install jumper J2 on the DWZZA–VA bus adapter to enable the singleended bus terminators.

The DWZZA–VA bus adapter and the HSZ10–AX controller are connected by
a 68-pin cable. Terminate the differential bus cables as follows:
–

Install differential bus terminators on the HSZ10–AX controller.

–

Install five SIP (single in-line package) resistors in the DWZZA–VA bus
adapter at the adapter end of the differential bus cable.

4–2 DWZZA–VA Bus Adapter

DWZZA–VA Bus Adapter
4.1 Major Features
Note
See the DWZZA–VA bus adapter documentation for jumper and SIP
installation procedures.

4.1.4 Terminator Power
The DWZZA–VA bus adapter supplies power to the SCSI terminators
(TERMPOWER). TERMPOWER is current limited by self-resetting fuses.

DWZZA–VA Bus Adapter 4–3

DWZZA–VA Bus Adapter
4.2 Disassembly of the DWZZA–VA Bus Adapter

4.2 Disassembly of the DWZZA–VA Bus Adapter
Remove the SBB bezel and the cover to install or remove bus terminators in the
DWZZA–VA bus adapter as shown in Figure 4–2. Both the bezel and cover are
secured with four mounting tabs. Use a small screwdriver to press in the ends of
the mounting tabs.
Figure 4–2 Typical 3½-Inch SBB

CASE

COVER
BEZEL

CXO-3645A-PH

CAUTION
Removing the DWZZA–VA bus adapter or disconnecting the SCSI cable
from the controller with power still active can cause the SCSI bus to
malfunction.
Do not perform this procedure until you have removed power from the
shelf.

4–4 DWZZA–VA Bus Adapter

DWZZA–VA Bus Adapter
4.2 Disassembly of the DWZZA–VA Bus Adapter
To change the DWZZA–VA bus adapter terminators, use the following procedure:
Step Procedure
1.

After removing power, disconnect the SCSI cable from the front of the DWZZA–VA
bus adapter and remove the adapter from the shelf.

Remove the bezel by pushing down on the end of the upper mounting tabs in the
base and cover while pulling the top of the bezel away from the SBB.

CAUTION
Use minimal pressure when pushing down on the mounting tabs to
prevent damage.
3.

Remove the cover by pushing down on the end of the upper mounting tabs while
pulling the top of the cover away from the base.

Configure the SCSI bus terminators by installing or removing the J2 jumper or the
five SIP resistors.

Replace the cover by inserting the bottom mounting tabs into the SBB base
mounting holes. Align the top mounting tabs with the base and snap the cover
into place.

Replace the bezel by inserting the bottom mounting tabs into the bottom mounting
holes in the base and cover. Align the top mounting tabs with mounting holes in the
base and cover and snap the bezel into place.

Install the SBB in the shelf, connect the SCSI cable, and apply power to the shelf.

Verify that the SCSI bus and devices are functioning properly.

4.3 Functional Specifications
The DWZZA–VA bus adapter meets the environmental specifications defined
in the BA350 Storage Shelf Subsystem User’s Guide for a DECstor/me modular
storage shelf subsystem. Table 4–2 lists the functional specifications of this
device.
Table 4–2 DWZZA–VA Bus Adapter Functional Specifications
Power requirements
Input voltage
Input current:
Electronics
Terminators
Maximum Power
Electrical interface

Connectors
Single ended

+5 Vdc, +/-0.25 volts.
1.5 amps.
0 to 3 amps.
TERMPOWER supplied to both buses.
22.5 watts.
Single-ended SCSI to differential SCSI.
8 bits plus parity.
Fast SCSI on both buses.
DECstor/me compatible 96-pin DIN Connector.
(continued on next page)

DWZZA–VA Bus Adapter 4–5

DWZZA–VA Bus Adapter
4.3 Functional Specifications
Table 4–2 (Cont.) DWZZA–VA Bus Adapter Functional Specifications
Differential
Termination
End-bus use
Mid-bus use
Single ended
Differential

68-pin panel mounted SCSI "P" connector.
Install or enable terminators.
Remove or disable terminators.
User selected 8-bit active termination (J2 installed =
enabled).
16-bit wide user removable resistors.

SCSI device address

No SCSI device addresses are used.

Overload protection

DTERMPOWER: 1.5 amp self-resetting thermal fuse.
STERMPOWER: 1.5 amp self-resetting thermal fuse.

Diode protection

DTERMPOWER isolated from Vcc by Schottky diodes.
STERMPOWER isolated from Vcc by Schottky diodes.

Shielding

SBB and differential connector shielded for ESD, EMI,
and safety requirements.

Replacement

The DWZZA–VA bus adapter can be replaced using the
hot swap method.
The DWZZA–VA bus adapter can be turned on or
off without inducing noise on either bus or causing
electrical malfunction.

RESET

Power-up reset and SCSI bus reset automatically clear
the initiator/target detection circuits and BSY noise
filter.

DECstor/me status signals

The DECstor/me single-ended TTL logic signals are
available on the following connector pins:
Single Ended
Connector Pin
20
22
30
34

Differential
Connector Pin
SWAP_L
40
SHELF_OK H
50
FAULT_CLK_H
55
FAULT_DATA_H
40

SCSI cable or bus length
Single-ended
Asynchronous
Synchronous
Differential

6 m (19.7 ft)
3 m (9.8 ft)
25 m (82 ft)

Cable fault signals

DEVIOUSNESS SCSI bus

Special features

BSY GLITCH TRAP†
Eliminates cable length constraint due to wired OR
noise on BSY line.

†Patent Pending

4–6 DWZZA–VA Bus Adapter

Index
5x1 SCSI bus
components
description,
configuration
description,
5x2 SCSI bus
components
description,
configuration
description,
5x3 SCSI bus
components
description,
configuration
description,
5x4 SCSI bus
components
description,
configuration
description,
5x5 SCSI bus
components
description,
configuration
description,
5x6 SCSI bus
components
description,
configuration
description,

3–4
3–4
3–6

Blowers
replacing, 1–7, 1–8

C
Configuration rules
BA350–EA shelf, 2–4
power supply, 2–1
SBBs, 2–1

3–6

3–14

DECstor/me products, 1–3
Device addressing rules
SBBs, 2–2
Device ID
DWZZA–VA bus adapter, 4–2
Differences from other DECstor/me shelves, 1–2
Documents
related, vi
DWZZA–VA bus adapter, 4–1
description, 4–1
device ID, 4–2
disassembly, 4–4, 4–5
functional specifications, 4–5
major features, 4–1
power supply, 4–3
SCSI cables, 4–2

3–14

3–8
3–8
3–10
3–10
3–12
3–12

A
Adapters
DWZZA–VA, 1–4
Address switch settings
SBBs, 2–2

B
BA350–EA shelf
components, 1–2
configuration rules, 2–4
controller section, 1–2
description, 1–1
dimensions, 1–1
storage section, 1–2
with HSZ10–AX controller, 3–2

Functional specifications
DWZZA–VA bus adapter, 4–5

H
HSx-series controllers
installation, 1–3
location, 1–3
HSZ10–AX controller
with BA350–EA shelf, 3–2
with SCSI bus, 3–2

Index–1

P
Power supply
configuration rules, 2–1
DWZZA–VA bus adapter, 4–3
location in shelf, 1–2
options, 1–2, 2–1
redundant, 1–2
requirements, 1–2, 1–3
Power supply LEDs
shelf status, 1–4

S
SBBs
address switch settings, 2–2
configuration rules, 2–1
definition, 1–1
device addressing rules, 2–2
removing, 1–7
replacing, 1–6, 1–7

Index–2

cold swap method, 1–7
hot swap method, 1–6
warm swap method, 1–7
SCSI bus
configuration, 3–1, 3–3
description, 3–3
procedure for configuration, 3–2
requirements, 3–1
with HSZ10–AX controller, 3–2
SCSI bus configuration
terminators, 4–2
SCSI cables
used with DWZZA–VA bus adapter, 4–2
Shelf status, 1–4
power supply LEDs, 1–4
SHELF_OK status signal, 1–6

T
Terminators
power supply, 4–3
SCSI bus, 4–2