Rockwell Automation 1764-xxxx MICROLOGIX 1500 PROGRAMMABLE CONTROLLERS - Manual (Page 74)

Publication 1764-UM001B-EN-P - April 2002
4-6 Communication Connections
Constructing Your Own Modem Cable
If you construct your own modem cable, the maximum cable length is
15.24 m (50 ft) with a 25-pin or 9-pin connector. Refer to the following
typical pinout for constructing a straight-through cable:
Constructing Your Own Null Modem Cable
If you construct your own null modem cable, the maximum cable
length is 15.24m (50 ft) with a 25-pin or 9-pin connector. Refer to the
following typical pinout:
AIC+ Optical Isolator
or 1764-LRP Channel 1 Modem
9-Pin 25-Pin 9-Pin
3 TXD TXD 2 3
2 RXD RXD 3 2
5 GND GND 7 5
1 CD CD 8 1
4 DTR DTR 20 4
6 DSR DSR 6 6
8 CTS CTS 5 8
7 RTS RTS 4 7
pins 4 and 6
are internally
connected for
1764-LRP only
Optical Isolator Modem
9-Pin 25-Pin 9-Pin
3 TXD TXD 2 3
2 RXD RXD 3 2
5 GND GND 7 5
1 CD CD 8 1
4 DTR DTR 20 4
6 DSR DSR 6 6
8 CTS CTS 5 8
7 RTS RTS 4 7