Minor Tx Alarms; Minor Rx Alarms - Radyne DMD20 Installation And Operation Manual

Maintenance and Troubleshooting

6.1.1.3 Minor Tx Alarms

Alarm
TerrClk (Terrestrial
Clock)
IntClk (Internal Clock)
TxSatCk (Tx Satellite
Clock)
Tx Data
TerrAIS (Terrestrial
AIS)
FllBack (Tx Clock
Fallback)
RS FIFO (Reed-
Solomon First In-First
Out)

6.1.1.4 Minor Rx Alarms

Alarm
Viterbi Lock
RxuProc (Receive
Processor)
Ext Ref (External
Reference PLL)
Ext EXC Act (External
Clock Activity)
HiStab (High-Stability
Oscillator)
BufUFLw (Buffer
Underflow)
BufOFLw (Buffer
Overflow)
6-4
Possible Cause
No Terrestrial Clock activity.
No SCT Clock activity.
No Tx Sat Clock activity when in
SCR Mode.
No Tx Data activity.
AIS (all ones) has been detected
in the Tx Data Stream.
Lack of an external clock forced
the Tx Clock to fall back to the
internal clock.
There is no Reed-Solomon FIFO.
Possible Cause
The Viterbi Decoder is not in a
locked state. Could be caused by
either the incoming signal or
internal circuit problems.
A hardware failure within the
modem.
The External Reference PLL
Circuit is not locked. Could be
caused by poor reference clock
supplied or internal circuit
problems.
The External Clock is not present
or the levels are out of range.
The High-Stability Oscillator is
active.
A Doppler Buffer underflow has
occurred.
A Doppler Buffer overflow has
occurred.
DMD20 Universal Satellite Modem
Action
Call the Radyne ComStream
Customer Service Center.
Call the Radyne ComStream
Customer Service Center.
Call the Radyne ComStream
Customer Service Center.
Call the Radyne ComStream
Customer Service Center.
Call the Radyne ComStream
Customer Service Center.
Verify the presence of an
external clock. If there is one
present, the Modem may need to
be replaced.
Call the Radyne ComStream
Customer Service Center.
Action
Call the Radyne ComStream
Customer Service Center.
The Modem may need to be
replaced.
Call the Radyne ComStream
Customer Service Center.
Check that the External
Reference Clock supplied to the
modem is present.
Call the Radyne ComStream
Customer Service Center.
Call the Radyne ComStream
Customer Service Center.
Call the Radyne ComStream
Customer Service Center.
TM103 - Rev. 1.1