User's Manual
DEFINITY ECS Release 8.2 Maintenance for R8.2csi 
555-233-119  Issue 1
April 2000
 Maintenance Objects
3-1066TDM-BUS (TDM Bus) 
3
Procedure 3
Procedure 3attempts to isolate the failure to a particular set of carriers, and then 
checks only the circuit packs in those carriers. This procedure involves 
terminating the TDM Bus so that certain carriers are disconnected from the TDM 
Bus. This is done by moving the TDM Bus terminators (AHF1) on the carrier 
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 the TDM Bus terminator. The TDM Bus terminators can be taken 
from one carrier to the other. To get to the TDM Bus cables, remove the back 
cover of the cabinet. When the length of the TDM Bus is modified via this 
procedure, the circuit packs that are essential to system operation and TDM Bus 
maintenance (for example, Network Control circuit pack, Tone-Clock circuit pack, 
Tone Detector circuit pack) must still be connected to the new 
shortened
 TDM 
Bus.
For the Processor Port Network (PPN)
1. Terminate the TDM Bus so that it extends within the control carrier.
2. Run the 
test tdm
 system technician command. If any of the TDM Bus tests 
fail, perform Procedure 2 and/or Procedure 3 for only the circuit packs in 
those carriers connected to the 
shortened
 TDM Bus. Procedure 2 is 
performed for port circuit packs (purple slots) and Procedure 3 for control 
carrier circuit packs.
3. If none of the TDM Bus tests fail, extend the TDM Bus to another carrier 
and repeat this procedure. When a carrier is added that causes some of 
the TDM Bus tests to fail, perform Procedure 2 and/or Procedure 3 for only 
the circuit packs in that carrier.
Restarting Nonfunctioning Port Circuit Packs
A defective TDM Bus Control Channel or system timing reference on one of the 
networks can result in port circuit packs (that is non-control carrier circuit packs) 
on this defective network entering the reset state. When this situation occurs, the 
circuit pack stops functioning and its red LED lights. The system does not detect 
the presence of a circuit pack when the circuit pack is in the reset state. Hence, 
executing the 
list config board PCSS
 command indicates that the circuit pack is 
not present.
If a circuit pack enters the reset state when the control channel is on TDM Bus PT 
(where network P contains the circuit pack), this circuit pack stops functioning 
until it receives a restart message when the control channel is on the same TDM 
Bus PT or when this circuit pack is powered up again.










