FCO DSRZA-F002 (DAS), Composite link probs w/flow control

This document is a Field Change Order (FCO DSRZA-F002) issued by Digital, addressing composite link problems with flow control that can cause MUXserver 100/DECmux II units to hang and result in incorrect CRC error counts.

The FCO applies to all DSRZA-BA/BB and 70-24216-01/02 units at revision C1 or lower. The recommended solution is to replace the existing MUXserver 100 with an updated REV D1 unit. Two kits are available based on AC input voltage: EQ-01577-02 for 120V units and EQ-01577-03 for 240V units.

A quick check involves verifying the Firmware version is V1.4-05 or checking for a REV D1 unit revision label. The FCO has a co-requisite: DFMZA-F002 (REV D1) must be installed on all attached DECmux II units, and software must be upgraded to V2.3 for this FCO to be effective.

Installation involves obtaining customer permission, recording existing MUXserver parameters (composite port and map characteristics), powering down and physically removing the old MUXserver 100, installing the new REV D1 unit (including setting internal switches if the RS422 option is used), ensuring the Network Manager updates the Ethernet address, powering on and verifying self-test, re-entering the recorded parameters, and finally, returning the server to the Network Manager for final reconfiguration and parameter reset. A small flat blade screwdriver is the only required tool, and the estimated Mean Time To Install (MTTI) is 1.0 hour.