Comtech EF Data SDM-300A, Installation And Operation Manual

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SDM-300A Satellite Modem Options
Rev. 4 A–49
A.1.5.1 IDR Specifications
Refer to Table A-15 for IDR specification.
Table A-15. IDR Specification
Primary Data Rates Supported
G.703 1544 kbit/s
2048 kbit/s
Engineering Service Channel
ESC Audio 2 channels at 32 kbit/s duplex ADPCM channel
ESC Data (Optional) 64 kbit/s duplex data (in place of audio channels)
Audio Encoding CCITT G.721
Audio Interface Type
600
Ω
transformer balanced 4-wire
Audio Input Level -20 to +10 dBm for 0 dBm, 1 dB steps
Audio Output Level -20 to +10 dBm for 0 dBm, 1 dB steps
Filtering Internal 300 to 3400 Hz, input and output
ESC Data Interface Type EIA-422
ESC Data Rate 8 kbit/s
ESC Data Circuits Supported SD, ST, RD, RT, Octet in, Octet out
Data Signal Phasing Per EIA-449, data changes on the rising clock transition, is
sampled on the falling clock edge
Octet Clock Pulse Octet high in with every 8th bit, aligns with frame bit d8
Faults and Alarms
Backward Alarms Supported 4 input, 4 output
Backward Alarm Inputs
1 k
Ω
pull up to +5V, set below 2V to clear
Backward Alarm Outputs Form C Relay, NO, NC, C
Demodulator Fault Relay NO, C contacts available for backward alarm inputs
Deferred Maintenance Alarm Open collector, high impedance IF fault, 15V maximum, 20 mA
maximum
Note: A 64 kbit/s data channel may be substituted for the two audio channels.