Vaisala PWD22 - Figure 14 Relay Connection: PWD22;52 Supplies; Table 8 Control Logic of Relay Controls 1, 2, and 3

Chapter 4 _______________________________________________________________ Installation
VAISALA _______________________________________________________________________ 41
Serial Multipoint Transmission RS-485
The RS-485 transmission standard allows several PWD22/52s to
communicate (half duplex) with the host computer using a single twisted
pair. For the RS-485 communication connect the PWD22/52 signal wires
to:
- BRN RS-485 A (+)
- WHT RS-485 B (-)
In some RS232/RS
-485 converters, the markings may be mixed. If the
connection does not work properly, switch the position of the wires.
The wiring and wire colors are identical in PWD11 and PWD22/52.
Connection of the Maintenance Terminal
Any computer equipped with terminal emulation software or a VT 100
compatible terminal with RS-232 serial interface can be used as a
Maintenance Terminal for PWD22/52.