Harris Constellation, Installation & Maintenance

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Constellation™ November 2003
10-8 Troubleshooting Guidelines
CARRIER LOSS
CARRIER LOSS A, B
Modem cannot lock on signal.
Fault may be in the Rx, path,
far-end Tx, far-end Modem,
near-end Modem (least likely).
CONFIG ALM
(configuration alarm)
Caused if 2 or more of the following
modules are changed
simultaneously:
Power Supply A1
Transmitter Assembly A1
SPU Controller
Use the Keypad to check the
configuration of the radio.
If all of the configuration are
correct, clear the alarm.
If not, reconfigure the radio.
Clearing the CONFIG ALM can drop traffic.
DEMOD
The HLM is not receiving proper
signals from the Modem.
Replace the Modem.
DS3-1, 2, 3, 4 BPV
Input signal in violation of bipolar
requirements at designated
channel.
Use the Keypad to verify the
signal coding.
CONFIGURATION >
TRIBUTARIES > CODE >
TRIBUTARY X CODE
DS3-1, 2, 3, 4 INPUT LOS No T3 signal present at designated
DS3 input.
Check DS3 input signals.
DS3-1, 2, 3, 4 LOOPBACK The signal on the channel is in
loopback mode locally.
Clear the loopback from local
radio.
CONTROL > TRIB LOOPBACK >
DS3 LPBK > CLR
DS3-1, 2, 3, 4 LPBK BY
REMOT
The signal on the channel is looped
back on HLM towards the Modem.
This signal was sent by remote
radio.
Clear loopback by remote from
remote radio.
DS3-1, 2, 3, 4 OUTPUT
FAIL
No DS3 output signal or signal level
too low (-3 dB) from the designated
DS3 channel.
Incorrect output load; failed
HLM/
DS3-1, 2, 3, 4 REMOTE
LPBK Loopback test of the channel from
the far end.
Clear remote loopback from
local radio.
CONTROL > TRIB LOOPBACK >
DS3 LPBK > CLR
DS3 LPBK
T3 signal is looped back on HLM
towards the Modem.
Clear the loopback from local
radio.
CONTROL > TRIB LOOPBACK >
DS3 LPBK > CLR
EXTERNAL ALARM (1-8)
Alarm input is at logic low or
ground. These are customer’s own
alarms.
Message Explanation
Course of Action/Possible
Causes