Automatic Clock Recovery - Nortel Meridian 1 Option 11C Manual

Reference clock errors
Meridian 1 software checks every 15 minutes to see if a clock controller or
reference clock error has occurred.
In tracking mode, the clock controller is tracking on one reference clock. If a
clock controller error is detected, or there is a problem with the reference
clocks, the system will switch to free run mode.
A reference clock error occurs when there is a problem with clock driver or
with the reference system clock at the far end. If the clock controller detects
a reference clock error, with only one of the reference clocks, the reference
clock is switched to the usable clock.
Figure 13
Clock controller primary and secondary tracking

Automatic clock recovery

Automatic switchover of the primary and secondary reference clocks is
always enabled in the Option 11C system.
Note: EREF and MREF commands in LD 60, which control the
enabling and disabling of automatic clock recovery, are not supported on
the Option 11C.
DTI/PRI
CC
DTI/PRI
DTI/PRI Maintenance
Primary
Reference
The primary reference clock is
supplied by the DTI/PRI which
supports the Clock Controller
daughter board.
Secondary
Reference
The secondary reference clock may
be supplied by any other DTI/PRI and
is routed to the Clock Controller
internal to the Option 11E system.
Option 11C
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