Comtech EF Data CDM-425, Инструкция по установке и эксплуатации

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CDM-425 Advanced Satellite Modem
Revision 0
Front Panel Operation 6–81 MN-CDM-425
Alarm Type Description
Tx
(Transmit)
No Clock
Clock activity from the Tx terrestrial source is checked if expected. The
modem falls back to the internal Serial Clock Transmit (SCT) clock to
drive the modulator if clock activity is absent.
FIFO Slip
Alarm occurs when the terrestrial clock source differs from the
programmed data rate, or may indicate a hardware failure.
Tx AIS
Alarm Indication Signal (all 1’s) is monitored at the Tx terrestrial input if
present.
AUPC Level
A Tx alarm occurs if the power increase limit has been reached when
AUPC is enabled.
Hi-Stab Freq Ref
Activity Fault
Reference not present; unit falls back to its internal 10MHz.
BUC summary alarm
May occur only if ABA is enabled.
G.703 Loss of Signal
May only occur in Clock Extension Mode.
PMSI Sym Clock Fail
In a CnC system where a 1:1 or 1:N redundancy switch is in use, this
alarm indicates that the PMSI symbol clock is not being detected in the
offline unit, suggesting a possible cable fault.
Rx
(Receive)
Demod Lock
Indicates either the demodulator or the following FEC decoder cannot
lock to the incoming signal.
AGC Alarm
Indicates if the demod signal level is out of range.
Frame Sync
Indicates that the de-framing unit (EDMAC) cannot synchronize to the
data being sent to it by the demod and/or FEC decoder.
CnC Lock
Indicates that the CnC cancellation algorithm has correctly converged
and is successfully tracking.
Buffer Slip
Occurs when Doppler or Plesiochronous effects cause the Rx data
buffer to empty or fill completely, which results in a reset to 50%.
Rx AIS
Alarm Indication Signal (all 1’s) is monitored if present at the Rx
satellite input.
EbNo Alarm
Occurs when the monitored level drops below what was programmed
via menus: Config, Rx, EbNo Alarm point.
Buffer Clock
Indicates that the desired buffer reference is not present, causing the
buffer to fall back on Rx satellite timing to clock its output.
BUC
Chapter 10. OUTDOOR UNIT (ODU) (TRANSCEIVER, BUC, AND LNB)
OPERATION
LNB