Comtech EF Data SDM-2020 - Manual (Page 120)

SDM-2020 Satellite Modulator Revision 7
ASI/RS-422 Data Interface MN/SDM2020M.IOM
9-5
Voh=12V max. and Vol=0.5V max. @ Iol=8 ma.
A pull-up resistor external to the equipment is required. The fault signals, MF and DF,
operate as follows: A fault is indicated by an “OFF” collector (high) and OK status is
indicated by an “ON” collector (low).
Table 9-2. RS-422 Connector Pinout (Per EIA-530), J5
Pin # Signal Function Name Type Comment
1 530 Shield Shield Mod/Demod
2 Transmit Data (TD-A) BA-A I Modulator
3 Receive Data (RD-A) BB-A O Demodulator
4 Request To Send (EIA-A) CA-A I Modulator
5 Clear To Send (CS-A) CB-A O Modulator
6 DCE Ready (DM-A) CC-A O Demodulator
7 Signal Ground AB GND
8 Receive Line Signal Detect (RR-A) CF-A O Demodulator
9 Receive Timing (RT-B) DD-B O Demodulator
10 Receive Line Signal Detect (RR-B) CF-B O Demodulator
11 Terminal Timing (TT-B) DA-B I Modulator
12 Send Timing (ST-B) DB-B O Modulator
13 Clear To Send (CS-B) CB-B O Modulator
14 Transmit Data (TD-B) BA-B I Modulator
15 Send Timing (ST-A) DB-A O Modulator
16 Receive Data (RD-B) BB-B O Demodulator
17 Receive Timing (RT-A) DD-A O Demodulator
18 N/C
19 Request To Send (EIA-B) CA-B I Modulator
20 DTE Ready (MC-A) CD-A I
21 Demodulator Fault (DF) DF O Demodulator
22 DCE Ready (DM-B) CC-B O Demodulator
23 DTE Ready (MC-B) CD-B I
24 Terminal Timing (TT-A) DA-A I Modulator
25 Modulator Fault (MF) MF O Modulator