| There are likely several responses to your query. The first thing would be to advise on what PBX specifically and moreover what your ultimate goal is with respect to your project.
Usually you will have a standard 9-pin or 25-pin RS-232 connection that will communicate in either a terminal interface or a printer port.
For you qwik-ref, here are the pinouts for your convenience.
*note these are for direct PC to modem connections and the 'null' versions to these are the reversals at one end for PC to PC type communications; [TxD-RxD | DTR-DSR | RTS-CTS]
9pin RS232:
1=CD
2=TxD
3=RxD
4=DTR
5=SG
6=DSR
7=RTS
8=CTS
9=RI
25-pin
2=TxD
3=RxD
4=RTS
5=CTS
6=DTR
7=SG
8=CD
20=DSR
22=RI
Please update your post with a few more specifics, if you may.
I hope this helps you moving forward. |