Ericsson LBI-39224 - Manual (Page 231)

LBI-39224
3-201
Clock Boards can be installed. Generally, two Clock Boards are
installed per CEC/IMC to allow uninterrupted operation when one
Clock Board must be removed for servicing. If two Clock Boards are
installed and the redundant clock feature is enabled, the toggle switches
are normally set at the factory as follows.
– Clock Board 1: Clock "A" is turned off and clock "B" is
turned on.
– Clock Board 2: Clock "A" is turned on and clock "B" is
turned off.
With the toggle switches set in this manner, clock "B" on Clock Board
1 is the utilized clock when the CEC/IMC is powered-up. If a clock
failure occurs the MOM will switch all Audio Boards to the "A" clock
and the "A" clock on Clock Board 2 will become the utilized clock.
Clock Board 1 can then be removed for service and the "B" clock on
Clock Board 2 can be turned on using the panel-mounted toggle switch
to maintain redundant clock operation.
If the redundant clock feature will be used, first verify the toggle
switches on the Clock Boards are correctly set as described above.
From the CEC/IMC Manager menu bar select
Configure System /
System Options / Redundant Clock to display the System Options
dialog box. The redundant clock feature is enabled/disabled from the
System Options dialog box.
Select the Redundant Clock check box to enable the redundant clock
feature. Redundant Clock is set on a local CEC/IMC "systemwide"