How to Use Data Communications
4WATLOW Series 945
19
20
21
22
23
T +
T -
R +
R -
Signal Common
(Optional)
Series 945 #
1
Series 945 #1
0
Twisted Pair Wire
12345
9
8
7
6
19
20
21
22
23
T +
T -
R +
R -
Signal Common
(Optional)
Twisted Pair Wire
T +
T -
R +
R -
Com
Host Computer(rear view)DB-9 femaleconnector(viewed from wire side)RS-422A

RS-422A Interface Pinouts

945A-XXXX-B000

The RS-422A communications uses a four wire (full duplex) system. There are

two separate lines for transmitting, and two lines for receiving data between the

computer and the Series 945. With RS-422A you can have from one to ten Series

945 controls connected to a single computer.

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.

Figure 1 -
RS-422A Interface,
Pin Designations.
NOTE:
The Electronic
Industry Association
(EIA) RS-422A
standard recom-
mends a maximum
4000 ft. total network
distance.