STRAT-3 (Stratum-3 Clock)
Issue 1 May 2002
8-1501555-233-143
f. This error type corresponds to FAIL code 16 of the Stratum-3 Clock Alarm
Query test (#649): every power supplied failed.
g. This error type corresponds to FAIL code 32 of the Stratum-3 Clock Alarm
Query test (#649): every clock unit failed.
h. An OFF-BOARD alarm on the Stratum-3 clock, indicates a DS1 facility
problem; an ON-BOARD alarm indicates a fault in either the Stratum-3
clock or the connection between the Stratum-3 clock and the switch. If the
Stratum-3 clock cannot be referenced and the local oscillator on the TN780
Tone-Clock circuit pack must serve as the reference, a Major alarm is
raised. Otherwise, a Minor alarm is raised.
i. This error can be caused by one of the following conditions:
■ One or both TOCs (Timing Output Cards) has failed.
■ The connection between the Stratum-3 clock and the TN780
Tone-Clock circuit pack is faulty.
■ The TN780 Tone-Clock circuit pack is defective.
A Minor alarm results if the Stratum-3 clock can still provide timing to the
switch; otherwise, a Major alarm will be raised because the Stratum-3 clock
is not providing timing and the switch is referencing the local oscillator on
the TN780 Tone-Clock circuit pack. If only the active TN780 Tone-Clock
circuit pack is faulty, the standby TN780 Tone-Clock circuit pack becomes
active and remains synchronized to the Stratum-3 clock. When the system
switches to the standby Tone-Clock circuit pack, the alarm is resolved, and
a TDM-CLK alarm is raised to indicate a possible problem on the TN780
Tone-Clock circuit pack.
If the alarm is minor:
Look for a red LED on either or both TOC cards. If there is a red
LED, then replace the card. If there is no red LED, then, using the
Stratum-3 Wiring Guide, check that the wiring installation is correct.
After replacing the card or correctly rewiring the installation, clear
the alarm by first issuing the disable synchronization-switch
command followed by the enable synchronization-switch
command. The latter procedure will cause synchronization software
to switch back to using the Stratum-3 clock again. Wait 2 minutes
and then execute the command. If Maintenance Name on the
status screen shows ‘‘STRAT-3,’’ then the problem is resolved.
!
CAUTION:
The disable synchronization-switch command followed by the
enable synchronization-switch command may cause slip alarms.
The circuit packs that can experience slips and the associated error
log entry for slips are as follows.
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