Table 2 – Vaisala WXT520 User Manual
Page 51
Chapter 5 _______________________________________________ Wiring and Power Management
VAISALA_______________________________________________________________________ 49
Table 2
Screw Terminal Pin-outs for WXT520 Serial
Interfaces and Power Supplies
Screw Terminal
Pin
RS-232
SDI-12
RS-485
RS-422
1 RX-
-
-
Data-
Data in (RX-)
2 RX+
-
-
Data+
Data in (RX+)
3 TX-
Data out (TxD)
Data in/out (Tx)
Data-
Data out (TX-)
4 TX+
-
-
Data+
Data out (TX+)
5 RXD
Data in (RxD)
Data in/out (Rx)
-
-
6 SGND
GND for data
GND for data
-
-
17 HTG-
GND for Vh+
GND for Vh+
GND for Vh+
GND for Vh+
18 HTG+
Vh+ (heating)
Vh+ (heating)
Vh+ (heating)
Vh+ (heating)
19 VIN-
GND for Vin+
GND for Vin+
GND for Vin+
GND for Vin+
20 VIN+
Vin+ (operating)
Vin+ (operating)
Vin+ (operating)
Vin+ (operating)
NOTE
In the true SDI-12 mode the two Data in/out lines must be combined
either in the screw terminal or outside WXT520.
NOTE
Short-circuit jumpers are required between pins 1-3 and 2-4 for the
RS-485 communication mode. For the RS-422 mode, the jumpers
should be removed. In the other modes the jumpers may stay or they
can be removed.