Comtech EF Data SDM-2020 User Manual
Page 132
SDM-2020 Satellite Demodulator
Revision 4
RS-422 Data Interface
MN/SDM2020D.IOM
7–6
Table 7-2. DVB Interface Connector Pinout, J3
Pin #
Signal Function/Name
Type
Comment
1 Clock
A
I/O Mod/Demod
2 System
GND/REFCLKB
O/GND Mod/Demod
Jumper selectable
SCT for Modulator
3
Data 7 A(MSB/Serial)
I/O
Mod/Demod
4
Data 6 A
I/O
Mod/Demod
5
Data 5 A
I/O
Mod/Demod
6
Data 4 A
I/O
Mod/Demod
7
Data 3 A
I/O
Mod/Demod
8
Data 2 A
I/O
Mod/Demod
9
Data 1 A
I/O
Mod/Demod
10
Data 0 A
I/O
Mod/Demod
11 DVALID
A
I/O
Mod/Demod
12 SYNC
A
I/O
Mod/Demod
13 Cable
Shield
I/O
Mod/Demod
14 Clock
B
I/O
Mod/Demod
15 System
GND/REFCLKA
O/GND Mod/Demod
Jumper selectable
SCT for Modulator
16
Data 7 B (MSB/Serial)
I/O
Mod/Demod
17
Data 6 B
I/O
Mod/Demod
18
Data 5 B
I/O
Mod/Demod
19
Data 4 B
I/O
Mod/Demod
20
Data 3 B
I/O
Mod/Demod
21
Data 2 B
I/O
Mod/Demod
22
Data 1 B
I/O
Mod/Demod
23
Data 0 B
I/O
Mod/Demod
24 DVALID
B
I/O
Mod/Demod
25 SYNC
B
I/O
Mod/Demod
7.3.1.2
Serial, J4, DB25 Female (EIA-530 Serial Data Interface)
This interface has no provision for SYNC or DVALID signals.
If framing is desired, a
sync byte (47 hex) is embedded into the data stream every 188 or 204 bytes, as selected
in the Demodulator configuration.
The Demodulator detects the sync byte and formats the
serial interface data into a standard, error-protected 204-byte packet.