Nortel Communication Server 1000S Maintenance Manual page 105

Procedure 16
Replacing the clock controller (Part 2 of 2)
Step Action
6 Set the ENB/DIS switch to DIS on the clock-controller card being added.
7 Make sure that the switch settings are correct.
8 Install new clock-controller card in same slot as the defective card.
9 Reconnect cable(s) to clock-controller faceplate.
10 Set ENB/DIS switch on new clock controller to ENB.
11 Enable new clock-controller card using:
LD 60
ENL CC x
12 Verify normal service level; first, switch the active clock to standby using:
LD 60
SWCK x
If an error message results, refer to Communication Server 1000M and Meridian 1:
Large System Maintenance (553-3021-500) for the interpretation.
Note: Switching clock controllers using LD 60 will generate ERR20 messages.
These can usually be ignored, but avoid excessive switching, especially when counters
are near the maintenance or out-of-service thresholds. Excessive switching can
generate maintenance or out-of-service threshold messages, or cause the PRI to be
disabled.
Check the counters in LD 60. If necessary, reset the counters using the RCNT
command.
Clock controller maintenance
ISDN Primary Rate Interface
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Maintenance