Demand test descriptions and error codes - Avaya Support

TDM-BUS (TDM Bus)
In this procedure, the TDM/LAN cable assemblies and TDM/LAN bus terminators are replaced.
If replacement does not resolve the TDM-bus fault, the cabinet is reconfigured so that certain
carriers are disconnected from the TDM bus. This is done by moving the TDM/LAN bus
terminators (ZAHF4) on the carrier’s backplane. To terminate a TDM bus at the end of a
particular carrier, the TDM bus cable that connects the carrier to the next carrier should be
unplugged and replaced with a TDM/LAN bus terminator (see Figure 87). As the length of a
TDM bus is modified, any essential circuit packs to the system’s operation and TDM-bus
maintenance (for example, Tone-Clock), must still be connected to the shortened TDM bus.
Figure 87: Carrier Rewiring Example — Rear View of 5-Carrier Cabinet
Carrier C
Carrier B
Carrier A
Fans
Carrier D
Carrier E
. . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . .
. . . . . . . . . . . . . .
Normally
Configured
Cabinet
(All 5 Carriers
TDM/LAN Bus Terminator
. . . . . . . . . . .
Bus Shortened
to Carrier A Only
(Control Carrier)
TDM/LAN Bus Cable
. . . . . . . . . . . . . .
. . . . . . . . . . . . . .
Shortened Bus
Extended to
Include
A and B
After cabling changes are made and verified, power must be restored to the PN. Circuit packs in
carriers outside the shortened bus are not inserted. As a result, these circuit packs are alarmed.
Ignore these alarms for now. Every alarm should be resolved when the cabinet is restored to its
original configuration.
Procedure 4 is organized into two parts. Part 1 attempts to clear a TDM-bus fault by replacing
every bus cable and terminator within a PN. Part 2 attempts to isolate the fault to a particular
carrier by extending the TDM bus from the control carrier to additional carriers one at a time.
Issue 5 May 2009 959