5
WATLOW Series 945
How to Use Data Communications

RS-423A Interface Pinouts (RS-232C Compatible)

945A-XXXX-B000

The RS-423A communications uses a three wire (full duplex) system. There is a

separate line for transmitting, a line for receiving data, and a line for signal common

between the computer and the Series 945. With RS-423A you can have only one

Series 945 control connected to a single computer or printer.

This diagram is a typical wiring example. The connections on the host computer

may vary depending on models. Refer to your computer user's manual for more

information.

945 #
1
20
21
23 Signal Common
R
T
Com
Host Computer
(rear view)
T
Jumper to Signal Common
123459
8
7
61011 12 13
1415 16 17 18 19 2 0 2122 23 24 25
R
RLSD (Received Line Signal Detector)
DSR (Data Set Ready)
RTS (Request To Send)
CTS (Clear To Send)
22
DB-25 female
connector
(viewed from wire side)
R, and RLSD together.
S
and CTS together.
m
puter's user manual.
DTR (Data Terminal Ready)
34
RS-423A
Figure 2 -
RS-423A Interface,
Pin Designations.
NOTE:
The Electronic
Industry Association
(EIA) RS-423A
standard recom-
mends a maximum
50 foot total point-
to-point distance.