Tiernan TDR60, Инструкция по установке и эксплуатации

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Troubleshooting 01-0868-401B 12/02 45
6 Troubleshooting
This chapter provides information on troubleshooting, including:
■
Fault reporting and monitoring
■
Initialization self-test function
■
Operational problems and their solutions
■
E
b
/N
0
, carrier offset, and link margin information
■
General maintenance
Fault Reporting and
Monitoring
The TDR60 has an internal micro-controller that continually performs real-time
monitoring of system conditions. When the unit detects a fault, one of the three
front panel LEDs are triggered, the fault it is stored in the fault history log and,
depending upon the type of fault, the fault may be viewed by querying the current
faults.
Front panel LED Indicators
At-a-glance system status is quickly determine by checking the front panel LED
indicators.
■
Status LED
❒
ON – the Status LED illuminates green when the demodulator, decoder,
and transport stream are all locked
❒
OFF – if the Status LED is not illuminated, at least one of the following is
unlocked: the demodulator, decoder, or transport stream.
■
Fault LED
❒
ON – the Fault LED illuminates amber when one or more system faults
exist.
❒
OFF – if the Fault LED is not illuminated, no current faults exist
■
Power LED
❒
ON – the Power LED illuminates green when the unit is powered on
❒
OFF – if the Power LED is not illuminated, the unit is powered off
Current Faults
Current faults are reported real-time , which means that only conditions that are
present at the time of the query are displayed, regardless of what fault conditions
have existed in the past.
Four types of problems generate a current fault on the TDR60:
■
Demultiplexer control FIFO overflow
■
Demultiplexer control input signal loss
■
QPSK demodulator bad E
b
/N
0
■
QPSK demodulator input signal loss
To determine if problems other than current faults exists, you must view the fault
history. All current faults are also recorded in the fault history log.