Black Box 945 - Manual (Page 5)

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
1
2
3
4
5
9
8
7
6
10
11
12
13
14
15
16
17
18
19
2 0
21
22
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.
mputer's user manual.
DTR (Data Terminal Ready)
3
4
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.