Comtech EF Data OM20 User Manual
Page 140

OM20 Universal Outdoor Modem
Maintenance and Troubleshooting
MN-OM20– Revision 5
7–2
Symptom
Possible Cause
The Modem will not acquire the
incoming carrier:
There is an improper receive input to modem.
The Receive Carrier Level is too low.
The Receive Carrier Frequency is outside of the acquisition
range.
The Transmit Carrier is incompatible.
Modem is in Test Mode.
The Async Port is not
configured correctly.
The switches may not be set in the correct positions.
7.2.1 Alarm Faults
7.2.1.1
Major Tx Alarms
Alarm
Possible Cause
FPGA CFG
Indicates a transmit FPGA hardware failure.
DSP CFG
Indicates a transmit FPGA failure.
SCT Clock PLL
Indicates that the Tx SCT Clock PLL is not locked. This
alarm will flash on during certain modem parameter
changes. A solid indication points toward a configuration
problem within the modem.
SYM Clock PLL
Indicates that the Tx Symbol Clock PLL is not locked. This alarm will
flash on during certain modem parameter changes. A solid indication
points toward a problem with the incoming clock to the modem (SCTE).
LB Synth PLL
Indicates that the Tx L-Band Synthesizer is not locked. This
alarm will flash on during certain modem parameter
changes. A solid indication points toward a configuration
problem within the modem.
IF Synth PLL
Indicates that the Tx IF Synthesizer is not locked. This
alarm will flash on during certain modem parameter
changes. A solid indication points toward a configuration
problem within the modem.
Ethernet WAN
Indicates that the WAN Port is down.