Hardware reference guide

CPU Modules
186
35013379 02 October 2007
Modbus
Connector
Pinouts
All Quantum CPUs are equipped with a nine-pin RS-232 connector that support
Modicon’s proprietary Modbus communication protocol. The following is the Modbus
port pinout connections for nine-pin and 25-pin connections.
Modbus Port
Modem Support
Modbus Port 1 has full modem interfacing ability. Modbus Port 2 RTS/CTS
connections function properly for normal non-modem communications but do not
support modems.
Modbus Ports
Pinout
Connections
Figure
The following figure shows the Modbus port pinout connections for 9-pin and 25-pin
connections.
Note: Although the Modbus ports electrically support existing Modbus cables, it is
recommended that a Modbus programming cable (Part # 990NAA26320 or
990NAA26350) be used. This cable has been designed to fit under the door of a
Quantum CPU or NOM module.
5
IBM-AT
9-Pin Female
Quantum
9-Pin Male
Quantum
9-Pin Male
IBM-XT
25-Pin Female
CD
RX
TX
DTR
GRND
DSR
RTS
CTS
1
2
3
4
5
6
7
8
1
2
3
4
6
7
8
9
SHIELD
RX
TX
DTR
GRND 5
DSR
RTS
CTS
NC
1
2
3
4
6
7
8
9
SHIELD
RX
TX
DTR
GRND
DSR
RTS
CTS
NC
RX
RTS
CTS
DSR
GRND
NC
1
2
3
4
5
6
7
8
SHIELD
TX
20DTR
This document provided by Barr-Thorp Electric Co., Inc. 800-473-9123 www.barr-thorp.com