Campbell Scientific WXT520 Weather Transmitter - Manual (Page 12)

WXT520 Weather Transmitter
6.5 Commands
Campbell Scientific uses the SDI-12 protocol to communicate with the
WXT520. Both "aM!" and "aR!" commands are supported (where "a" is the
sensor address). The preferred command is "aR!", since the communication is
done in fewer steps. The WXT520 is configured to run continuously so the
output is identical. TABLE 6-2 contains the outputs as configured by Campbell
Scientific. All outputs are in SI units.
TABLE 6-2. SDI-12 Commands
SDI-12
Command Command
Function
Values Returned
aR! or aM! Composite
Message Wind Direction Average, Wind Speed
Average, Air Temperature, Relative
Humidity, Barometric Pressure, Rainfall
Amount, Hail Amount
aR1! or
aM1! Wind Message Wind Direction Minimum, Wind Direction
Average, Wind Direction Maximum, Wind
Speed Minimum, Wind Speed Average,
Wind Speed Maximum
aR2! or
aM2! PTU Message Air Temperature, Relative Humidity,
Barometric Pressure
aR3! or
aM3! Precipitation
Message Rainfall Amount, rainfall Duration, Rainfall
Intensity, Hail Amount, Hail Duration, Hail
Intensity
aR5! or
aM5! Self Diagnostic
Message Supply Voltage, Internal Reference Voltage
6.6 Programming
6.6.1 CRBasic
Dataloggers that use CRBasic include our CR200(X)-series, CR800, CR850,
CR1000, CR3000, and CR5000. These dataloggers use the SDI12Recorder()
instruction to read the WXT520.
The SDI12Recorder() instruction has the following form:
SDI12Recorder(Destination, Output String, Multiplier, Offset)
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