Comtech EF Data SDM-100A - Manual (Page 199)

SDM-100A Satellite Modem Options
Rev. 0 B–17
B.2.2.4 Utility/Interface
With ADPCM turned off, the RS-422 signals SD, RD, RR, and DM can be inverted, if
desired.
B.2.2.5 TX Alarm Indication
With the ADPCM option turned on, the TX alarm LED will come on if an excessive
input level is sensed on the TX+ and TX- lines of the interface.
B.2.2.6 RX Alarm Indication
With the ADPCM option turned on, the RX alarm LED will come on if an excessive
input level is received by the DEMUX.
B.2.2.7 DEMUX Lock
With the ADPCM option turned on, the DEMUX alarm will become active if the
demultiplexer loses lock.
B.2.2.8 Remote Off Hook
With the ADPCM option turned on, the Remote Off Hook alarm will become active if an
indication is detected that the receiving station has taken the receiver off the hook.