Avaya S8700 Maintenance Manual page 2331

TDM-CLK (TDM Bus Clock)
h. Error Type 1281
has detected a loss of timing signal from the system's synchronization
reference. The Tone-Clock circuit has switched synchronization
references.
1. Resolve any errors logged against the SYNC or STRAT-13 MOs.
2. See
Error Type 1282
synchronized to a DS1 facility and that the reference frequency provided by
the DS1 drifted beyond a range that could be tracked by the TN2182.
Therefore the TN2182 is no longer synchronized to that DS1 reference. If
a second DS1 is available, the tone-clock may be synchronized to that
reference. If no secondary DS1 reference is available, the tone-clock will
run off of its internal clock. This may result in slips being reported by the
tone-clock and every DS1 facility.
i. The Tone-Clock circuit in the master port network was unable to detect the
incoming synchronization signal, but the other tone-clock was able to
detect the references. If the aux data is 0, the problem is with the signal on
the primary. If the aux data is 1, the problem is with the signal on the
secondary. The system should switch clocks in this situation.
1. If this error is against EPN 1's clock board and the system is using a
2. Replace the current standby IPSI or Tone-Clock circuit pack. See
j. The indicated active Tone-Clock circuit, which is in an EPN that does not
contain the system's synchronization reference (a slave Tone-Clock), has
detected a loss of timing signal from its EXP-INTF synchronization source.
1. Enter display errors and display alarms, and follow the associated
2. If the 2305 errors persist, follow the repair procedures for EXP-INTF
555-233-143

This error is an indication that the Tone-Clock circuit
''SYNC (Port-Network Synchronization)''
"Approach to Troubleshooting" section, if the error is not resolved by
step 1

Indicates that the TN2182 tone-clock was
Stratum-3 clock, check the cabling that brings the Stratum-3 signal
to this clock board.
''Replacing the IPSI or Tone-Clock Circuit Pack'' on page
repair procedures for EXP-INTF, TDM-CLK, and TONE-BD error log
entries that have on-board alarms.
error log entries 257, 769, or 770, or any errors logged against
SNI-BD, SNC-BD, or FIBER-LK.
maintenance, in the
8-1666.
Issue 1 May 2002 8-1609