Issue 5     November 2000   
363-206-208
Troubleshooting
Lucent Technologies - Proprietary
See Notice on first page
(5) If the TGSs are not working as described, verify that the timing mode selection 
is set properly. In a remote terminal (RT), the TGS should be set for loop-timed. 
In a central office (CO), the TGS should be set for external if the DDM-2000 is 
being supplied an external DS1 clock and free-running if a clock is not available. 
(6) If the TGS is set properly for external timing and a problem still exists, discon-
nect the external timing and set the TGS for free-running. 
(7) If a problem still exists with the TGS, try the failed unit in the other TGS slot. If 
the TGS fails in both slots, replace the TGS circuit pack. If the TGS fails in only 
one slot, replace the shelf. 
(8) In each muldem, if one function unit (3DS3) is installed, its ACTIVE LED should 
be lighted. If two function units are installed, one should have its ACTIVE LED 
lighted and the other should have no LED lighted. 
(9) If a solid FAULT LED is lighted on any circuit pack, determine if the problem 
exists with the shelf or the pack. 
(10)If the FAULT LED is flashing on the SYSCTL, the shelf is having difficulty com-
municating over the data communication channel to the far end. Determine if the 
problem is with the transmission path [that is, optical line interface units (OLIUs) 
with flashing FAULT LEDs] or with the SYSCTL at the far end.  
Troubleshooting with a Terminal
(1) Diagnostic information is provided by the DDM-2000 using the rtrv 
(RETRIEVE) commands. 
(2) Use the rtrv-alm (RETRIEVE-ALARM) command to display the alarms that 
the DDM-2000 is reporting. 
(3) Use the rtrv-eqpt (RETRIEVE-EQUIPMENT) command to display the equip-
ment installed in the DDM-2000. 
(4) Use the rtrv-state (RETRIEVE-STATE) command to display the state (which 
packs are active/standby, type of protection switching) of the DDM-2000. 
(5) If problems still persist, refer to or 363-206-290 (Release 5) or  363-206-295 
(Release 7), DDM-2000 OC-12 Multiplexer User/Service Manual.