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

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Specifications SDM-300A Satellite Modem
C–44 Rev. 4
C.7.2.3 EIA-449/EIA-422 Mil-188-114A Specification
EIA-449/EIA-422 Mil-188-114A Specification
Circuit Supported SD, ST, TT, RD, RT, DM, RR, RS, CS, MC
Amplitude (RD, RT, ST, DM, RR)
±
2V differential into 100
Ω
Impedance (RD, RT, ST, DM, RR)
Less than 100
Ω
, differential
Impedance (SD, TT, MC)
4k
Ω
True when B is positive with respect to A
False when A is positive with respect to B
Phasing (RD, RT) False-to-true transition of RT nominally in center of RD data
bit
Symmetry (ST, TT, RT)
50%,
±
5%
Circuit Assignments
SD-A, SD-B Send Data
ST-A, ST-B Send Timing
RD-A, RD-B Receive Data
RS-A, RS-B Request to Send
RT-A, RT-B Receive Timing
CS-A, CS-B Clear to Send
DM-A, DM-B Data Mode
RR-A, RR-B Receiver Ready
TT-A, TT-B Terminal Timing
MC-A, MC-B Master Clock
MF Mod Fault (ttl)
DF Demod Fault (ttl)
C.7.2.4 G.703 (Optional with Overhead Card)
G.703 Specification
Primary Data Circuits Supported T1 SD, RD
E1 SD, RD
Interface Type Transformer coupled symmetrical pair
Data Rates
T1 1544 kbit/s,
±
100 bit/s
E1 2048 kbit/s,
±
130 bit/s
Pulse Width
T1 324,
±
50 Ns
E1 244,
±
25 Ns
SD Amplitude
T1 3V +0.3/-1.5V-pk into 100
Ω
E1 3V +0.3/-1.5V-pk into 120
Ω
RD Amplitude
T1 3V +0.3/-1.5V-pk into 100
Ω
E1 3V +0.3/-1.5V-pk into 120
Ω
Pulse Mask T1 G.703.2
E1 G.703.6
Jitter Attenuation T1 G.824
E1 G.823
Line Code AMI (T1 or E1)
B8ZS (T1 only)
HDB3 (E1 only)