Vaisala HMT330 - Manual (Page 60)

User's Guide _______________________________________________________________________
58 ___________________________________________________________________ M210566EN-K
1102-023
Figure 36 RS-422/485 Module
The following numbers refer to Figure 36 above:
1 = Flat cable pins
2 = Selection switches
3 = Screw terminals for wiring
NOTE The data lines on earlier versions of the RS-422/485 module are marked
A and B instead of D1+ and D0-. When the line is idle, D1+ has positive
voltage compared to D0-.
When connecting the module, be prepared to swap the D1+ and D0-
wires if you have a communication problem.
Installation and Wiring
1. Disconnect the power. In case the RS-422/485-module is installed
in the factory, continue with the item 4.
2. Open the transmitter cover and attach the RS-422/485 module to
the bottom of the housing with four screws.
3. Connect the flat cable between the RS-422/485 module and the
motherboard's pins MODULE1 (Communications).
4. Pull the network wirings through the cable gland.
1
2
3