1-23. Timing Source Selection - Continued.
CNCE or External Standard at Each End. In this example, both TD-1337(V)/G's have selected CNCE
or external standard as the timing source. In turn, each group input that meets the necessary
criteria can be selected as a source. From these, the TD-1337(V)/G will select one of the group
inputs as the timing source. In the event of failure of this source, the TD-1337(V)/G will automatically
switch to one of the remaining sources. In the event all sources are lost, the TD-1337(V)/G will
switch to a slave condition.
In this example, a CNCE or external standard timing source exists at only one location. Therefore,
the other TD-1337(V)/G has selected slave as its timing source. Slave timing is regulated by control
data that is automatically transmitted/received in the SG.
In this example, a CNCE or external standard timing source is not available. Therefore, one TD-
1337(V)/G will be designated a master and the other will be a slave. The master operates from
its own internal timing source.