Serial Multipoint Transmission Rs-485; Connection Of The Maintenance Terminal - Vaisala PWD22/52 User Manual

Chapter 4 _______________________________________________________________ Installation
NOTE
NOTE
VAISALA _______________________________________________________________________ 39

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
- WHT
In some RS232/RS-485 converters the markings may be mixed. If the
connection does not work properly, switch the position of the wires.
In PWD11 User's Guide the RS-485 markings were mixed. The markings
are corrected in this manual. The actual 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.
RS-485 A (+)
RS-485 B (-)