Vaisala WXT510 - Manual (Page 134)

User’s Guide ______________________________________________________________________
132 _________________________________________________________________ M210470EN-D
Communication Protocol
Set the communication protocol SDI-12 v 1.3 (aXU,C=1,M=S) or SDI-
12 v1.3 continuous (aXU,C=1,M=R).
WXT510s on the bus shall be assigned with different addresses (for
example: aXU,A=0,1,2, ... ). Thereafter WXT510s on the bus do not
respond to the commands not assigned to them nor to the data messages
sent by the other WXT510s.
Example (A bus with three WXT510s):
WXT510 #1 communication settings:
0XXU,A=0,M=S,C=1,B=1200,D=7,P=E,S=1, L=25
WXT510 #2 communication settings:
1XXU,A=1,M=S,C=1,B=1200,D=7,P=E,S=1, L=25
WXT510 #3 communication settings:
2XXU,A=2,M=S,C=1,B=1200,D=7,P=E,S=1, L=25
If simultaneous measurements of the different units are needed, Start
concurrent measurement commands aC and aCC should be use for all
devices. If the measurements are to be performed consecutively for only
one unit at time, in addition to these also Start measurement commands
aM and aMC can be used. Start continuous measurement commands
aR1, aR2, aR3, aR5, aR, aRC1, aRC2, aRC3, aRC5 and aRC
available only in SDI-12 continuous protocol (aXU,M=R) can be used
eiher for simultaneous measurements of the units or consecutive
measurements for one unit at time. See also
SDI-12 Protocol on page
67 .
RS-485 Serial Interface
Wiring
1. Make the RS-485 wiring of WXT510 as described in Chapter 5,
Wiring and Power Management, on page 35 .
2. In the data logger end, combine the "Data +" wires of each
WXT510 to the logger "Data +" wire. Connect the "Data-" wires of
each WXT510 to the logger "Data -" wire.