Vaisala · Weather station
WXT530 series weather transmitter (WXT531 / WXT532 / WXT533 / WXT534 / WXT535 / WXT536) Modbus register map
Default configuration
- Protocol
- RS485
- Port
- 502
- Unit ID
- 1
- Addressing
- 0-based
- Byte order
- Big endian
- Word order
- High word first
- Baud rate
- 19200
- Parity
- Even
- Data bits
- 8
- Stop bits
- 1
This device has an RS-485 interface. Reach it through a Modbus RTU-to-TCP gateway, configured with the factory serial settings above.
Register map
| Address | Count | Name | Type | Unit | Scale | Access |
|---|---|---|---|---|---|---|
| 0 | 1 | Device identification High byte = WXT530 model (WXT531 = 01 ... WXT536 = 06), low byte = last digits of the software version number. | Hex | - | 1 | R |
| 2 | 1 | Available parameters, temperature and dew point Per-parameter availability according to the WXT530 model: 00 = available, 07 = not available. | Hex | - | 1 | R |
| 3 | 1 | Available parameters, relative and absolute humidity 00 = available, 07 = not available. | Hex | - | 1 | R |
| 4 | 1 | Available parameters, mixing ratio and air pressure 00 = available, 07 = not available. | Hex | - | 1 | R |
| 5 | 1 | Available parameters, wind and rain 00 = available, 07 = not available. | Hex | - | 1 | R |
| 6 | 1 | External sensors at analog inputs Solar radiation sensor (high byte) and level sensor (low byte): 00 = connected, 07 = not connected. | Hex | - | 1 | R |
| 7 | 1 | External sensors at analog inputs, temperature and rain gauge Temperature sensor (high byte) and rain gauge (low byte): 00 = connected, 07 = not connected. | Hex | - | 1 | R |
| 10 | 1 | Relative humidity, instant Scaling factor 10 in the document. | Int16 | %RH | 0.1 | R |
| 11 | 1 | Relative humidity, minimum Minimum over the averaging period set in holding register 0x0002. | Int16 | %RH | 0.1 | R |
| 12 | 1 | Relative humidity, maximum Maximum over the averaging period set in holding register 0x0002. | Int16 | %RH | 0.1 | R |
| 13 | 1 | Relative humidity, average Average over the averaging period set in holding register 0x0002. | Int16 | %RH | 0.1 | R |
| 14 | 1 | Relative air pressure, instant Derived from air temperature, relative humidity, pressure and the altitude in holding register 0x0000. | Int16 | hPa | 0.1 | R |
| 15 | 1 | Relative air pressure, minimum Minimum over the averaging period set in holding register 0x0003. | Int16 | hPa | 0.1 | R |
| 16 | 1 | Relative air pressure, maximum Maximum over the averaging period set in holding register 0x0003. | Int16 | hPa | 0.1 | R |
| 17 | 1 | Relative air pressure, average Average over the averaging period set in holding register 0x0003. | Int16 | hPa | 0.1 | R |
| 18 | 1 | Wind direction, instant Scaling factor 10 in the document. | Int16 | ° | 0.1 | R |
| 19 | 1 | Wind direction, minimum Minimum over the wind averaging period set in holding register 0x0004. | Int16 | ° | 0.1 | R |
| 20 | 1 | Wind direction, maximum Maximum over the wind averaging period set in holding register 0x0004. | Int16 | ° | 0.1 | R |
| 21 | 1 | Wind direction, average Average over the wind averaging period set in holding register 0x0004. | Int16 | ° | 0.1 | R |
| 22 | 1 | Wind direction, raw Raw wind direction sample. | Int16 | ° | 0.1 | R |
| 25 | 1 | Precipitation type 0 = no precipitation, 40 = precipitation, 90 = hail. | Int16 | - | 1 | R |
| 26 | 1 | Wind measurement quality Scaling factor 1 in the document (0...100 %). | UInt16 | % | 1 | R |
| 27 | 1 | Global radiation, instant Solar radiation from a pyranometer on the analog input (WXT536). | Int16 | W/m2 | 0.1 | R |
| 28 | 1 | Global radiation, minimum Minimum over the averaging period set in holding register 0x0005. | Int16 | W/m2 | 0.1 | R |
| 29 | 1 | Global radiation, maximum Maximum over the averaging period set in holding register 0x0005. | Int16 | W/m2 | 0.1 | R |
| 30 | 1 | Global radiation, average Average over the averaging period set in holding register 0x0005. | Int16 | W/m2 | 0.1 | R |
| 31 | 1 | Air temperature, instant Scaling factor 10 in the document. Range -50.0...60.0 °C. | Int16 | °C | 0.1 | R |
| 32 | 1 | Air temperature, minimum Minimum over the averaging period set in holding register 0x0002. | Int16 | °C | 0.1 | R |
| 33 | 1 | Air temperature, maximum Maximum over the averaging period set in holding register 0x0002. | Int16 | °C | 0.1 | R |
| 34 | 1 | Air temperature, average Average over the averaging period set in holding register 0x0002. | Int16 | °C | 0.1 | R |
| 35 | 1 | Dew point, instant Derived from air temperature and relative humidity. | Int16 | °C | 0.1 | R |
| 36 | 1 | Dew point, minimum Minimum over the averaging period set in holding register 0x0002. | Int16 | °C | 0.1 | R |
| 37 | 1 | Dew point, maximum Maximum over the averaging period set in holding register 0x0002. | Int16 | °C | 0.1 | R |
| 38 | 1 | Dew point, average Average over the averaging period set in holding register 0x0002. | Int16 | °C | 0.1 | R |
| 39 | 1 | Wind chill temperature, instant Derived from air temperature, relative humidity and wind (JAG/TI 2001). | Int16 | °C | 0.1 | R |
| 41 | 1 | Heater temperature, instant Range -50.0...150.0 °C. | Int16 | °C | 0.1 | R |
| 42 | 1 | Wind speed, instant Scaling factor 10 in the document. Range 0...75.0 m/s. | Int16 | m/s | 0.1 | R |
| 43 | 1 | Wind speed, minimum Minimum over the wind averaging period set in holding register 0x0004. | Int16 | m/s | 0.1 | R |
| 44 | 1 | Wind speed, maximum Maximum over the wind averaging period set in holding register 0x0004. | Int16 | m/s | 0.1 | R |
| 45 | 1 | Wind speed, average Average over the wind averaging period set in holding register 0x0004. | Int16 | m/s | 0.1 | R |
| 47 | 1 | Wind speed, raw Raw wind speed sample (1 s of 250 ms samples). | Int16 | m/s | 0.1 | R |
| 48 | 1 | Precipitation accumulation, absolute Continuous accumulated precipitation since the last counter reset; write 0x3247 to holding register 0x0007 to reset. Scaling factor 100 in the document; saturates at 655.30 mm. | UInt16 | mm | 0.01 | R |
| 49 | 1 | Precipitation accumulation, differential Accumulated precipitation between two consecutive requests. Scaling factor 100 in the document. | UInt16 | mm | 0.01 | R |
| 50 | 1 | Precipitation intensity Scaling factor 100 in the document; range 0...200.00 mm/h. | UInt16 | mm/h | 0.01 | R |
| 71 | 1 | Absolute humidity, instant Derived from air temperature, relative humidity and pressure. | Int16 | g/m3 | 0.1 | R |
| 72 | 1 | Absolute humidity, minimum Minimum over the averaging period set in holding register 0x0002. | Int16 | g/m3 | 0.1 | R |
| 73 | 1 | Absolute humidity, maximum Maximum over the averaging period set in holding register 0x0002. | Int16 | g/m3 | 0.1 | R |
| 74 | 1 | Absolute humidity, average Average over the averaging period set in holding register 0x0002. | Int16 | g/m3 | 0.1 | R |
| 75 | 1 | Mixing ratio, instant Mass mixing ratio derived from air temperature, relative humidity and pressure. | Int16 | g/kg | 0.1 | R |
| 76 | 1 | Mixing ratio, minimum Minimum over the averaging period set in holding register 0x0002. | Int16 | g/kg | 0.1 | R |
| 77 | 1 | Mixing ratio, maximum Maximum over the averaging period set in holding register 0x0002. | Int16 | g/kg | 0.1 | R |
| 78 | 1 | Mixing ratio, average Average over the averaging period set in holding register 0x0002. | Int16 | g/kg | 0.1 | R |
| 83 | 1 | Wind speed, instant (km/h) Same sample as input register 0x002A, in km/h. | Int16 | km/h | 0.1 | R |
| 84 | 1 | Wind speed, minimum (km/h) Minimum over the wind averaging period set in holding register 0x0004. | Int16 | km/h | 0.1 | R |
| 85 | 1 | Wind speed, maximum (km/h) Maximum over the wind averaging period set in holding register 0x0004. | Int16 | km/h | 0.1 | R |
| 86 | 1 | Wind speed, average (km/h) Average over the wind averaging period set in holding register 0x0004. | Int16 | km/h | 0.1 | R |
| 98 | 1 | Wet bulb temperature, instant Temperature of a moist or icy surface exposed to airflow. | Int16 | °C | 0.1 | R |
| 101 | 1 | Air density Scaling factor 1000 in the document; range 0...3.000 kg/m3. | Int16 | kg/m3 | 0.001 | R |
| 107 | 1 | External temperature, instant Pt1000 on the WXT536 analog input, -40.0...80.0 °C. | Int16 | °C | 0.1 | R |
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Related guides
Notes
Source: Vaisala 'Vaisala Weather Transmitter WXT530 Series User Guide', M211840EN-G ((c) Vaisala 2023): Appendix B 'Modbus protocol' - Table 57 default settings and the B.2 register maps (Tables 58-64). The guide is not exposed as a PDF on a Vaisala download page (docs.vaisala.com serves the guide as versioned web help; the PDF links tried under vaisala.com return 404), so the PDF was read from the public distributor mirror https://download.ambismart.io/Vaisala/WXT530_v386/WXT530-M211840EN-G-User's%20Guide.pdf, SHA-256 104956f5632a2a19aa674b2b0c9feb8e4da34d1929b306f087e1f29256b2d774 (MIRROR-SOURCED). Modbus RTU is available from firmware 3.85 onwards and needs the WXT53XU... order code. Factory settings: default address 1 (Table 57) and RS-485 Modbus RTU 19200 baud, 8, E, 1 (Table 24). Addressing: the register tables print a 1-based 'Reg. no' next to the hex 'Address' (Reg. 1 = 0x0000, Reg. 11 = 0x000A); the hex addresses are stored unchanged as zero-based wire addresses. Scaling: the document's SF column is a divisor, so every scale_factor is 1/SF (temperature 0.1 °C, pressure 0.1 hPa, wind 0.1 m/s, precipitation 0.01 mm, air density 0.001 kg/m3). 16-bit values use the document's error convention: 65535 = unavailable unsigned, 32767 = unavailable signed. Included: device-status block, the unit-independent RH/pressure/wind-direction/precipitation-type/radiation block, the metric block and the unit-independent derived values (absolute humidity, mixing ratio, wind in km/h, wet bulb temperature, air density, external temperature) plus all 11 holding registers. Left out: the imperial block (input registers 52-71) with its other-unit duplicates - wind in knots (0x0058-0x005B), raw km/h and knots (0x005D-0x005E), wet-bulb °F (0x0063), external temperature °F (0x006C), raw wind quality (0x006D) - plus absolute air pressure (0x004F-0x0052) and specific enthalpy (0x0064) as scope choices, the reserved rows, and input registers 9-10 (0x0008-0x0009), unlisted by the guide.