J4, db25 f, Eia-530 s – Comtech EF Data SDM-2020 User Manual
Page 105
SDM-2020 Satellite Modulator
Revision 7
RS-422 Data Interface
MN/SDM2020M.IOM
7-6
7.1.4.2
S
ERIAL
, J4, DB25 F
EMALE
(EIA-530 S
ERIAL
D
ATA
I
NTERFACE
)
This interface has no provision for SYNC or DVALID signals. If framing is desired, a
sync byte (47 hex) is imbedded into the data stream every 188 or 204 bytes, as selected in
the modulator configuration. The modulator detects the sync byte and formats the serial
interface data into a standard, error-protected 204-byte packet.
7.1.4.2.1
Connector Pinouts, J4, EIA-530
The connector is a subminiature, 25-pin, female D connector, with threaded jack nuts.
Signal functions are as defined in EIA-530.
The differential sense of all signals is logic “1” when “B” is positive with respect to “A”
as defined in EIA-530. Only those pins indicated as “modulator” in the table are
applicable.
Table 7-3. EIA-530 Serial Interface Connector Pinout (J4)
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
Master Clock (MC-A)
N/A
I
Demodulator
21 Demodulator
Fault
(DF)
N/A O Demodulator
22
DCE Ready (DM-B)
CC-B
O
Demodulator
23
Master Clock (MC-B)
N/A
I
Demodulator
24
Terminal Timing (TT-A)
DA-A
I
Modulator
25
Modulator Fault (MF)
N/A
O
Modulator