Rockwell Automation 1746-BAS-T SLC 500 Basic Basic-T Modules - Manual (Page 46)

Publication 1746-UM004B-EN-P - December 2005
3-12 Install and Wire Your Module
DCE - Data Communication Equipment
Devices such as modems are Data Communication Equipment (DCE).
The pinouts on these terminals are defined for ease of interfacing with
DTE equipment.
Figure 3.9 RS-232/423 Wiring Diagram - Module to a Modem (Hardware
Handshaking Enabled)
DCE 9 Pinout Signal from DCE
Perspective
DCE 25
Pinout
Pin # Signal Description Pin #
1 CD-Carrier Detect Output 8
2 RXD-Received Data Output 3
3 TXD-Transmitted Data Input 2
4 DTR-Data Terminal Ready Input 20
5 Com-Signal Common Shared 7
6 DSR-Data Set Ready Output 6
7 RTS-Request to Send Input 4
8 CTS-Clear to Send Output 5
9 RI-Ring Indicator Output 22
IMPORTANT
All signal directions listed in the previous two tables
are valid. For example, TXD, Transmitted Data, is a
DTE output but is also a DCE input. The signal
description is the same for both the DTE and DCE
but the direction of the signal (perspective) has
changed based on whether you have a DTE or DCE
device.
N.C. 1
RXD 2
TXD 3
DTR 4
COM 5
DSR 6
RTS 7
CTS 8
N.C. 9
CD
RXD
TXD
DTR
COM
DSR
RTS
CTS
RI
8
3
2
20
7
6
4
5
22
1
2
3
4
5
6
7
8
9
Basic DTE DCE 9-pin 25-pin