Comtech EF Data CDM-600/600L - Manual (Page 114)

CDM-600/600L Open Network Satellite Modem Revision 3
Front Panel Operation MN/CDM600L.IOM
5–38
UNIT
PSU
Power supplies (+5V, +12V, -5V, +18V, -12V) are always monitored
by an onboard supervisory IC.
Tx and Rx Synth
The PLLs in the IF sections are monitored for an unlocked condition.
Power Cal
Calibration data stored in EEPROM is checked at power up to verify
that the factory calibration has not been corrupted.
FPGA
Downloads are verified to have been loaded successfully.
Hi-Stab Freq Ref
Module (CDM-600) No PLL Lock – This will suppress the Tx carrier.
Internal Reference
SYNTH (CDM-600L)
NET (Unit
Network)
Lose TxFrm
Loss of Tx frame occurs in Drop & Insert operation, when the
incoming T1 or E1 frame cannot be found by the modem.
BER >10E-3
This error rate monitor is enabled for IBS and IDR framing.
Lose TxMul
Loss of Tx multiframe occurs in E1-CAS D&I operation, when the
multiframe marker for CAS signaling data cannot be found.
Tx Sig AIS
An AIS condition in the signaling positions of an incoming E1-CAS
frame is monitored.
Tx Terr RM
Indicates the presence of the Tx terrestrial remote alarm on the
incoming T1 or E1 frame.
IBS Rx Rem
Indicates the presence of the IBS satellite remote alarm (backward
alarm) on the incoming IBS frame from the transmit side of the link.
IDR Rx BW1-4
Multi-destinational backward alarms are the corresponding satellite
alarms used by the IDR frame structure.
IDR Tx BW1-4
Backward alarms 1-4 indicate that the hardware inputs available on
the back panel of the modem have triggered, resulting in the
corresponding Tx backward alarm being generated by the modem’s
IDR framer
RECV
(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, IBS or IDR) or Reed-
Solomon outer decoder cannot synchronize to the data being sent to
it by the demod and/or FEC decoder.
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) present at the Rx satellite input is
monitored.
EbNo Alarm
Occurs when the monitored level drops below that programmed by
the user 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.
LNB Fault Information
(CDM-600L)