Comtech EF Data CRS-311 - Manual (Page 179)

CRS-311 1:1 Redundancy Switch Revision 7
Appendix B MN/CRS311.IOM
B–11
B.2.8 CRS-351 – Overhead Module Connector (DB-25M)
Table B‐11 indicates pinout for the DB‐25M Overhead “User Interface” connector: “P1” on the
CRS‐351 Overhead Module. This connector 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.
Table B-11. “P1” Overhead User Data Connector
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 ‐).