Specifications

SDM-300L3 Satellite Modem Revision 0
Specifications MN/SDM300L3.IOM
15–38
15.15.1 D&I Primary Data Interfaces
When configured for D&I operation, multiplexing/demultiplexing follows the IBS satellite
frame structure and ESC features, but with the following changes:
• Accepts and outputs primary data through the 50-pin connector using G.703. The
data rate must be at T1 or E1 rates only.
• This includes additional links for Drop Data Out and Insert Data In. Clock
recovery, dejitter, and encoding/decoding are performed as before.
15.15.2 D&I Framing
The IBS satellite framing/deframing is applied only to selected time slots of the data’s
G.704 terrestrial structure.
15.16 IDR (Optional with Overhead Card)
Primary Data Rates Supported
G.703 1544 kbps SD, RD
2048 kbps SD, RD
Engineering Service Channel
ESC Audio 2 duplex ADPCM channels
Audio Encoding CCITT G.721
Audio Interface Type
600Ω 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
Audio Filtering Internal 300 to 3400 Hz input and output
ESC Data Interface Type EIA-422
ESC Data Rate 8 kbps, also 64 kbps if ADPCM audio is not used
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 Timing 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
1KΩ 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 faulted, 15V maximum, 20 mA
maximum