Comtech EF Data CDM-625A Installation And Operation Manual page 204

CDM-625A Advanced Satellite Modem
Front Panel Operation
Alarm Type
Rx
(Receive)
Net (Unit
Network)
BUC
LNB
Description
Indicates either the demodulator or the following FEC decoder cannot
Demod Lock
lock to the incoming signal.
AGC Alarm Indicates if the demod signal level is out of range.
Indicates that the de-framing unit (EDMAC, IBS or IDR) or Reed-
Frame Sync Solomon outer decoder cannot synchronize to the data being sent to it
by the demod and/or FEC decoder.
Indicates that the CnC cancellation algorithm has correctly convaerged
CnC Lock
and is successfully tracking.
Occurs when Doppler or Plesiochronous effects cause the Rx data
Buffer Slip
buffer to empty or fill completely, which results in a reset to 50%.
Alarm Indication Signal (all 1's) is monitored if present at the Rx
Rx AIS
satellite input.
Occurs when the monitored level drops below what was programmed
EbNo Alarm
via menus: Config, Rx, EbNo Alarm point.
Indicates that the desired buffer reference is not present, causing the
Buffer Clock
buffer to fall back on Rx satellite timing to clock its output.
Loss of Tx frame occurs in Drop & Insert operation, when the incoming
Loss TxFrm
T1 or E1 frame cannot be found by the modem.
BER >10E-3 This error rate monitor is enabled for IBS and IDR framing.
Loss of Tx multiframe occurs in E1-CAS D&I operation, when the
Loss TxMul
multiframe marker for CAS signaling data cannot be found.
An AIS condition in the signaling positions of an incoming E1-CAS
Tx Sig AIS
frame is monitored.
Indicates the presence of the Tx terrestrial remote alarm on the
Tx Terr RM
incoming T1 or E1 frame.
Indicates the presence of the IBS satellite remote alarm (backward
IBS Rx Rem
alarm) on the incoming IBS frame from the transmit side of the link.
Multi-destination backward alarms are the corresponding satellite
IDR Rx BW1-4
alarms used by the IDR frame structure.
Backward alarms 1-4 indicate that the hardware inputs available on the
IDR Tx BW1-4
back panel of the modem have triggered, resulting in the generation, by
the modem's IDR framer, of a corresponding Tx backward alarm.
Chapter 10. CDM-625A ODU (TRANSCEIVER, BUC, LNC) OPERATIONS
6–80
MN-CDM625A
Revision 4