Maintenance-Object Repair Procedures
555-233-143
8-1130 Issue 1 May 2002
A synchronization switch takes place if half or more of the MMI circuit packs in a
PN report a loss of synchronization. For example, a PN with two MMIs reporting a
loss of sync source switches immediately, three and four MMIs switch if two report
the loss, and so forth. A healthy MMI circuit pack becomes the master
synchronization source providing the signal on a new timeslot. The other MMI
circuit packs within the PN are instructed to listen to this new signal, and the old
master stops providing the signal and now listens to the new master MMI. If an
MMI is physically removed from the system, then the remaining MMIs report the
loss of synchronization. The first MMI with no alarms present becomes the new
master of that PN. Once a synchronization switch has occurred, another switch is
not allowed for 15 minutes to avoid hyperactive switching. If every MMI has an
alarm, then no switch is made.
If the MMI circuit pack that provides synchronization is craft busied out, it will not
affect the PN synchronization. The signal is still provided by the busied-out pack.
There is no effect on synchronization if the technician issues a release of the
busied-out MMI. Synchronization is not affected by a warm start of the system
(reset system 1). For every other restart (reboot through cold 2), MMI
synchronization recovers during board insertion.
Error Log Entries and Test to Clear Values
System Technician-Demanded Tests:
Descriptions and Error Codes
There are no system technician-demanded tests for MMI-SYNC.
Table 8-465. MMI-SYNC Error Log Entries
Error
Type
Aux
Data Associated Test Alarm Level
On/Off
Board Test to Clear Value
1 Any None See note
1
1. An MMI synchronization switch was successful. Refer to MMI-BD errors for the reason for the switch.
257 Any None MINOR OFF See note
2
2. The requested MMI synchronization switch failed. Resolve every MMI-BD alarm.
To Next Page
Loading...
