Rockwell Automation 1766-Lxxxx MicroLogix 1400 Programmable Controllers User Manual - Manual (Page 80)

66 Rockwell Automation Publication 1766-UM001H-EN-P - May 2014
Chapter 4 Communication Connections
MicroLogix 1400 Channel 0 to Modem Cable Pinout
When connecting MicroLogix 1400 Channel 0 to a modem using an RS-232
cable, the maximum that the cable length may be extended is 15.24 m (50 ft).
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:
ATTENTION: Do not connect pins 1 and 8. This connection will
cause damage to the RS-232/485 communication port (channel 0)
of the MicroLogix 1400 and/or the controller itself.
DTE Device
(MicroLogix
1400
Channel 0) DCE Device
(Modem,
PanelView,
etc.)
8-Pin 25-Pin 9-Pin
7 TXD TXD 2 3
4 RXD RXD 3 2
2 GND GND 7 5
1 B(+) DCD 8 1
8 A(-) DTR 20 4
5 DCD DSR 6 6
6 CTS CTS 5 8
3 RTS RTS 4 7
AIC+ Optical Isolator
or 1766-LEC Channel 2 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
1766-LEC only