Operating instructions

Maintenance and Troubleshooting DMD20/DMD20 LBST Universal Satellite Modem
6-4 TM103 – Rev. 2.8
6.1.1.4 Minor Rx Alarms
Alarm Possible Cause
BUFF UNDERFLOW Indicates that a Doppler Buffer underflow has occurred.
BUFF NEAR EMPTY Indicates that the Doppler Buffer is about to underflow.
BUFF NEAR FULL Indicates that the Doppler Buffer is about to overflow.
BUFF OVERFLOW Indicates that a Doppler Buffer overflow has occurred.
RX DATA ACTIVITY Indicates that there is no Rx Data activity. For the Ethernet
Interface, indicates that no Ethernet port is active (no cable
is plugged in).
SAT AIS Indicates that AIS has been detected in the receive satellite
data stream.
DnI FRAME LOCK Indicates if drop/insert data is frame locked.
DnI M-FRAME LOCK
Indicates if drop/insert data has multiframe lock.
INSERT CRC Indicates if the Circular Redundancy Check is passing in
PCM-30C and PCM-31C Modes.
T1/E1 SIGNALING Indicates that the T1/E1 Signal is not locked.
IFEC LOCK Indicates that the Inner Codec is not locked.
OFEC LOCK Indicates that the Reed-Solomon Decoder is not locked.
INTERLEAVER Indicates that the Reed Solomon Interleaver is not
synchronized.
EBNO (dB) Indicates that the Eb/No is outside of limits.
IBS BER Indicates that there are more than one in 1000 bits in error
in IBS mode.
RX DVB FRAME LOCK Indicates that the Rx Satellite Data Stream Framing is not
DVB.
LNB CURRENT Indicates that current is either below or above the threshold
limits of the BUC, as specified by the modem. Only active
when voltage is enabled.
LNB VOLTAGE Indicates that voltage is not functioning correctly when
voltage is enabled.