SLM-5650 Satellite Modem
Revision 2
Installation
MN/SLM5650.IOM
2–10
2.3.10 Overhead Data, (P1)
The overhead interface connector is a 25-pin male D interface located on the rear panel of the
modem.
This connector pin-out allows for connection of EIA-422, EIA-485 and EIA-232 data interfaces
for use with overhead framing. It also supports signaling for tactical applications
Pin #
Signal Function
Name
1
EIA-422 Transmit Data “A”, Input
Tx Data A
14
EIA-422 Transmit Data “B”, Input
Tx Data B
2
EIA-422 Transmit Clock “A”, Output
Tx Clk A
15
EIA-422 Transmit Clock “B”, Output
Tx Clk B
3
EIA-422 Transmit Byte Sync “A”, Output
Tx Sync A
16
EIA-422 Transmit Byte Sync “B”, Output
Tx Sync B
4
EIA-422 Receive Data “A”, Output
Rx Data A
17
EIA-422 Receive Data “B”, Output
Rx Data B
5
EIA-422 Receive Clock “A”, Output
Rx Clk A
18
EIA-422 Receive Clock “B”, Output
Rx Clk B
6
EIA-422 Receive Byte Sync “A”, Output
Rx Sync A
19
EIA-422 Receive Byte Sync “B”, Output
Rx Sync B
7 Shield
Ground
20
EIA-485 Transmit Data “-“
485 Tx Data -
8
EIA-485 Transmit Data “+”
485 Tx Data +
21
EIA-422 Transmit Handover Sync “A”, Input
THS A
9
EIA-485 Receive Data “-“
485 Rx Data -
22
EIA-485 Receive Data “+”
485 Rx Data +
10
EIA-422 Transmit Handover Sync “B”, Input
THS B
23
EIA-232 Clear to Send
232 CTS
11
EIA-232 Receive Data
232 Rx Data
24
EIA-232 Request to Send
232 RTS
12
EIA-232 Transmit Data
232 Tx Data
25
EIA-422 Transmit Handover Control “A”, Input
THC A
13
EIA-422 Transmit Handover Control “B”, Input
THC B
*For EIA-485 2-Wire Operation:
•
Only two wires are required.
•
Tie pins 8 and 22 together (both +).
•
Tie pins 9 and 20 together (both -).
