Vaisala WXT530 Series
Compact weather transmitter that measures wind, rain, air temperature, humidity and air pressure in one housing.
The Vaisala WXT530 series is a family of compact weather transmitters that measure wind, rain, air temperature, humidity and air pressure on a roof or mast, for example above a greenhouse. This Modbus RTU template reads all weather values with their minimum, maximum and average, and lets you set altitude, averaging intervals, heating and the rain counter reset from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 102, read and write
- Brand
- Vaisala
- Key readings
- Air temperature · Relative humidity · Air pressure · Wind speed · Wind direction · Precipitation intensity · Precipitation accumulation · Global radiation
- Available commands
- Altitude · Averaging intervals · Heating control · Rain counter reset · Wind direction offset · Modbus address
- Compatible models
- WXT531 · WXT532 · WXT533 · WXT534 · WXT535 · WXT536
- Last updated
Registers (102)
102 read, 11 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Air Temperature | °C | Read | |||
| Air Temperature Min | °C | Read | |||
| Air Temperature Max | °C | Read | |||
| Air Temperature Avg | °C | Read | |||
| Relative Humidity | %RH | Read | |||
| Relative Humidity Min | %RH | Read | |||
| Relative Humidity Max | %RH | Read | |||
| Relative Humidity Avg | %RH | Read | |||
| Relative Air Pressure | hPa | Read | |||
| Relative Air Pressure Min | hPa | Read | |||
| Relative Air Pressure Max | hPa | Read | |||
| Relative Air Pressure Avg | hPa | Read | |||
| Absolute Air Pressure | hPa | Read | |||
| Absolute Air Pressure Min | hPa | Read | |||
| Absolute Air Pressure Max | hPa | Read | |||
| Absolute Air Pressure Avg | hPa | Read | |||
| Wind Speed | m/s | Read | |||
| Wind Speed Min | m/s | Read | |||
| Wind Speed Max | m/s | Read | |||
| Wind Speed Avg | m/s | Read | |||
| Wind Speed Raw | m/s | Read | |||
| Wind Direction | ° | Read | |||
| Wind Direction Min | ° | Read | |||
| Wind Direction Max | ° | Read | |||
| Wind Direction Avg | ° | Read | |||
| Wind Direction Raw | ° | Read | |||
| Precipitation Intensity | mm/h | Read | |||
| Precipitation Accumulation | mm | Read | |||
| Precipitation Accumulation Differential | mm | Read | |||
| Precipitation Type | Read | ||||
| Global Radiation | W/m² | Read | |||
| Global Radiation Min | W/m² | Read | |||
| Global Radiation Max | W/m² | Read | |||
| Global Radiation Avg | W/m² | Read | |||
| External Temperature | °C | Read | |||
| Dew Point | °C | Read | |||
| Dew Point Min | °C | Read | |||
| Dew Point Max | °C | Read | |||
| Dew Point Avg | °C | Read | |||
| Wind Chill Temperature | °C | Read | |||
| Wet Bulb Temperature | °C | Read | |||
| Absolute Humidity | g/m³ | Read | |||
| Absolute Humidity Min | g/m³ | Read | |||
| Absolute Humidity Max | g/m³ | Read | |||
| Absolute Humidity Avg | g/m³ | Read | |||
| Mixing Ratio | g/kg | Read | |||
| Mixing Ratio Min | g/kg | Read | |||
| Mixing Ratio Max | g/kg | Read | |||
| Mixing Ratio Avg | g/kg | Read | |||
| Specific Enthalpy | Read | ||||
| Air Density | Read | ||||
| Heater Temperature | °C | Read | |||
| Wind Measurement Quality | % | Read | |||
| Wind Measurement Quality Raw | % | Read | |||
| Air Temperature (°F) | °F | Read | |||
| Air Temperature Min (°F) | °F | Read | |||
| Air Temperature Max (°F) | °F | Read | |||
| Air Temperature Avg (°F) | °F | Read | |||
| Dew Point (°F) | °F | Read | |||
| Dew Point Min (°F) | °F | Read | |||
| Dew Point Max (°F) | °F | Read | |||
| Dew Point Avg (°F) | °F | Read | |||
| Wind Chill Temperature (°F) | °F | Read | |||
| Heater Temperature (°F) | °F | Read | |||
| Wind Speed (mph) | Read | ||||
| Wind Speed Min (mph) | Read | ||||
| Wind Speed Max (mph) | Read | ||||
| Wind Speed Avg (mph) | Read | ||||
| Wind Speed Raw (mph) | Read | ||||
| Precipitation Accumulation (in) | Read | ||||
| Precipitation Accumulation Differential (in) | Read | ||||
| Precipitation Intensity (in/h) | Read | ||||
| Wet Bulb Temperature (°F) | °F | Read | |||
| External Temperature (°F) | °F | Read | |||
| Wind Speed (km/h) | km/h | Read | |||
| Wind Speed Min (km/h) | km/h | Read | |||
| Wind Speed Max (km/h) | km/h | Read | |||
| Wind Speed Avg (km/h) | km/h | Read | |||
| Wind Speed Raw (km/h) | km/h | Read | |||
| Wind Speed (knots) | Read | ||||
| Wind Speed Min (knots) | Read | ||||
| Wind Speed Max (knots) | Read | ||||
| Wind Speed Avg (knots) | Read | ||||
| Wind Speed Raw (knots) | Read | ||||
| Temperature And Dew Point Availability | Read | ||||
| Humidity Availability | Read | ||||
| Mixing Ratio And Air Pressure Availability | Read | ||||
| Wind And Rain Availability | Read | ||||
| Solar Radiation And Level Sensor Status | Read | ||||
| Temperature Sensor And Rain Gauge Status | Read | ||||
| Altitude | m | Read and write | |||
| Wind Direction Deviation Angle | ° | Read and write | |||
| Averaging Interval Temperature And Humidity | min | Read and write | |||
| Averaging Interval Air Pressure | min | Read and write | |||
| Averaging Interval Wind | min | Read and write | |||
| Averaging Interval Solar Radiation | min | Read and write | |||
| Heating Control | Read and write | ||||
| Modbus Address | Read and write | ||||
| Reset Rain Accumulation Counter | Read and write | ||||
| Reset Device | Read and write | ||||
| CLI Mode | Read and write | ||||
| Device Identification | Read |
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If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Show outside temperature, humidity, wind speed and rain intensity from the greenhouse roof on a dashboard next to the indoor climate.
- Get an alert by email or webhook when the average wind speed or the rain intensity passes a threshold you set.
- Keep 365 days of weather history to compare outside temperature, radiation and rain with energy use or crop results.
- Reset the rain counter or change an averaging interval from ModbusCloud without climbing onto the roof.
- Follow the wind measurement quality and the heater temperature to see when snow or ice affects the wind readings.
Installation
Check that the transmitter has the RS-485 Modbus option and firmware 3.85 or newer. An existing unit can be switched to Modbus through the service port with the Vaisala Configuration Tool.
Connect Data+ (gray wire) and Data- (blue wire) to the RS485 terminals of the ModbusCloud Gateway. Power the transmitter with 5 to 32 V DC on the brown (+) and red (-) wires.
Leave the termination jumper inside the transmitter on NO, unless it sits at the end of a long RS485 line; then select R (121 Ω).
In ModbusCloud, add a Modbus device with address 1, 19200 baud, 8 data bits, even parity and 1 stop bit, and import this template.
Check that air temperature or wind speed shows a plausible value. A value stuck at 3276.7 is reported by the transmitter as invalid or not available.
Things to watch for
The transmitter does not answer. What should I check?
It only answers in Modbus mode, which needs the RS-485 Modbus option or a switch-over with firmware 3.85 or newer. Check 19200 baud, 8 data bits, even parity, 1 stop bit and address 1, and swap Data+ and Data- if needed. Unplug the service cable: while it is connected, the main port is disabled.
Why does a value stay at 3276.7 or 655.35?
That is the code for an invalid or unavailable value after scaling. A model reports it for quantities it does not measure, such as wind on a WXT534, or global radiation on a WXT536 without a pyranometer. The availability values show what your model provides.
Why did the rain accumulation drop to zero or stop rising?
Precipitation Accumulation counts continuously and stops at 655.30 mm until you reset it. A switch between CLI and Modbus mode and a write to the rain counter reset also set it to zero. The differential value is the rain since the previous request, so it depends on how often the gateway reads.
Can I change settings from ModbusCloud?
Yes. Altitude, wind direction offset, averaging intervals, heating and Modbus address are writable, and writing 12871 to Reset Rain Accumulation Counter clears the rain counters. Writing 15 to CLI Mode takes the transmitter out of Modbus, after which it stops answering. Writes use function 16 only. Writing is off per gateway by default; request it in the portal.
How often should ModbusCloud read the transmitter?
Vaisala advises not to poll faster than the value is updated, for example once a minute for average values. The default ModbusCloud interval of 5 minutes fits that.
Want to see how it works?
