Comtech EF Data C5 - Manual (Page 242)

System Checkout C5/K1/K3 Integrated Satellite Terminal System
Rev. 0 6-18
Fault/Alarm Possible Problem and Action
BUFFER CLK
PLL Buffer clock phase-locked loop fault. The buffer synthesizer is the wrong frequency or
will not lock.
Ensure the selected buffer clock source is at the proper frequency and level. If the fault
continues, contact the EFData Customer Support Department.
BUFFER CLK
ACT Activity detector alarm of the selected interface receive clock.
The interface will fall back to the satellite clock when this fault is active.
DEMUX_LOCK Demultiplexer synchronization lock fault. This fault means that the demultiplexer is
unable to maintain valid frame and multiframe alignment.
The usual cause is invalid or absent receive data. This is a major (prompt) alarm. The
alarm will cause insertion of receive AIS (all 1s) and the switch-over will be attempted.
This fault is to be sent as a backward alarm to the distant end. This fault will occur
when no carrier is present, but will probably never occur with a correct signal.
RX 2047 LOCK RX 2047 lock alarm.
Indicates the RX 2047 data test pattern is not being received by the decoder. The alarm
probably indicates the transmitter is not set correctly.
BUFFER FULL Buffer full alarm.
Indicates the buffer is < 10% or > 90% full.