Vaisala HMP60 / HMP110
Humidity and temperature probe for greenhouses, incubators and equipment, with dew point and enthalpy.
The Vaisala HMP60 and HMP110 are compact humidity and temperature probes that measure relative humidity and temperature in greenhouses, incubators and equipment. This Modbus RTU template reads humidity, temperature, dew point, absolute humidity, mixing ratio, wet-bulb temperature, enthalpy and the error code, and lets you set the filtering, the serial settings and the humidity and temperature adjustment from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 55, read and write
- Brand
- Vaisala
- Key readings
- Relative humidity · Temperature · Dew/frost point · Absolute humidity · Mixing ratio · Wet-bulb temperature · Enthalpy · Error code
- Available commands
- Measurement filtering factor · Modbus address · Bit rate and parity · Response delay · Humidity and temperature adjustment · Device restart
- Compatible models
- HMP60 · HMP63 · HMP110 · HMP110T · HMP113 · HMP115 · HMP115T · TMP115
- Last updated
Registers (55)
52 read, 35 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Relative Humidity | %RH | Read | |||
| Temperature | °C | Read | |||
| Dew/Frost Point Temperature | °C | Read | |||
| Absolute Humidity | g/m³ | Read | |||
| Mixing Ratio | g/kg | Read | |||
| Wet-Bulb Temperature | °C | Read | |||
| Enthalpy | Read | ||||
| Relative Humidity (Integer) | %RH | Read | |||
| Temperature (Integer) | °C | Read | |||
| Dew/Frost Point Temperature (Integer) | °C | Read | |||
| Absolute Humidity (Integer) | g/m³ | Read | |||
| Mixing Ratio (Integer) | g/kg | Read | |||
| Wet-Bulb Temperature (Integer) | °C | Read | |||
| Enthalpy (Integer) | Read | ||||
| Error Status | Read | ||||
| Error Code | Read | ||||
| Security Hash | Read | ||||
| Measurement Filtering Factor | Read and write | ||||
| Modbus Address | Read and write | ||||
| Bit Rate | Read and write | ||||
| Parity, Data and Stop Bits | Read and write | ||||
| Response Delay | ms | Read and write | |||
| Protocol | Read and write | ||||
| Restart Device | Write | ||||
| Calibration Mode Passcode | Read and write | ||||
| Calibration Year | Read and write | ||||
| Calibration Month | Read and write | ||||
| Calibration Day | Read and write | ||||
| Calibration Text | Read and write | ||||
| RH Adjustment Reference Point 1 | %RH | Read and write | |||
| RH Adjustment Measured RH Point 1 | %RH | Read and write | |||
| RH Adjustment Measured T Point 1 | °C | Read and write | |||
| RH Adjustment Reference Point 2 | %RH | Read and write | |||
| RH Adjustment Measured RH Point 2 | %RH | Read and write | |||
| RH Adjustment Measured T Point 2 | °C | Read and write | |||
| RH Adjustment Reference Point 3 | %RH | Read and write | |||
| RH Adjustment Measured RH Point 3 | %RH | Read and write | |||
| RH Adjustment Measured T Point 3 | °C | Read and write | |||
| RH Adjustment Reference Point 4 | %RH | Read and write | |||
| RH Adjustment Measured RH Point 4 | %RH | Read and write | |||
| RH Adjustment Measured T Point 4 | °C | Read and write | |||
| RH Adjustment Reference Point 5 | %RH | Read and write | |||
| RH Adjustment Measured RH Point 5 | %RH | Read and write | |||
| RH Adjustment Measured T Point 5 | °C | Read and write | |||
| Activate RH Adjustment | Read and write | ||||
| Restore Factory RH Adjustment | Write | ||||
| T Adjustment Reference Point 1 | °C | Read and write | |||
| T Adjustment Measured T Point 1 | °C | Read and write | |||
| T Adjustment Reference Point 2 | °C | Read and write | |||
| T Adjustment Measured T Point 2 | °C | Read and write | |||
| Activate T Adjustment | Read and write | ||||
| Restore Factory T Adjustment | Write | ||||
| Signed Integer Test | Read | ||||
| Floating Point Test | Read | ||||
| Text String Test | Read |
Loading registers…
Send your device list
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 humidity, temperature and dew point per greenhouse compartment on a dashboard and keep 365 days of history.
- Get an email, in-app or webhook alert when relative humidity rises above or drops below the level the crop needs.
- Plot the dew point next to the air temperature to see when the greenhouse air comes close to condensation.
- Raise an alert when Error Status is 0 or Error Code is not 0, for example on a wet humidity sensor or a supply voltage out of range.
- Export absolute humidity, mixing ratio and enthalpy as CSV or in a PDF report for climate and energy analysis.
- Raise the measurement filtering from the portal when short swings in the reading need to be averaged out.
Installation
Connect pin 4 (RS-485+, black wire) and pin 2 (RS-485-, white) of the Vaisala M8 cable to the RS485 port of the ModbusCloud Gateway, and pin 3 (blue) to ground. Do not add termination resistors, Vaisala advises against them.
Power the probe with 5 to 28 V DC on pin 1 (brown). Use the lowest voltage that suits the installation, because a higher voltage warms the probe slightly.
Make sure the probe is in Modbus mode with address 240, 19200 baud, no parity, 8 data bits and 2 stop bits. Switch a probe ordered with analog output to Modbus with Vaisala Insight. Give each probe on the bus its own address.
In ModbusCloud, add a Modbus device on the gateway with these settings and import the Vaisala HMP60 / HMP110 template.
Check that Floating Point Test reads -123.45 and that Relative Humidity and Temperature show plausible values.
Things to watch for
The probe does not answer on the RS485 bus. What should I check?
Check 19200 baud, no parity, 8 data bits and 2 stop bits at address 240. Many masters default to 1 stop bit. Check that RS-485+ is on pin 4 and RS-485- on pin 2, and swap them if nothing answers. A probe ordered with analog output stays silent until it is switched to Modbus, for example with Vaisala Insight. Probes with software older than 2.1.4 have no Modbus. After power-up the probe needs up to 2 seconds before it answers.
The humidity looks plausible but does not match my reference. How do I check the readout?
Read Floating Point Test. It must show -123.45, and Signed Integer Test -12345. The probe sends 32-bit values low word first, and a wrong word order can still give values that look right. The template already uses the order of the probe. On the temperature-only models HMP110T, HMP115T and TMP115 only the temperature registers carry a measurement.
Error Status shows 1. Is something wrong with the probe?
No. On this probe Error Status 1 means no errors and 0 means one or more errors are active. Error Code then shows the cause as a sum of codes, for example 2 for a humidity measurement error, which usually means a wet sensor, or 2048 for a supply voltage out of range. An alert on Error Code not equal to 0 catches every error.
Writing a setting returns an error or has no effect. Why?
The probe only accepts writes as write multiple (function code 16). The filtering factor and the adjustment values are 32-bit and always go that way. If writing a single 16-bit setting such as the address or the bit rate returns an error, change it with Vaisala Insight. New serial settings only apply after a restart. Writing registers in ModbusCloud is off by default and is enabled per gateway on request.
Can I calibrate the probe from ModbusCloud?
The template contains the adjustment registers, but Vaisala recommends its calibration service, Vaisala Insight or a compatible handheld meter. An adjustment needs a stable reference humidity or temperature, the passcode 1300 to open calibration mode, and some registers written together in one go, such as the calibration date and text. You can follow the probe values in ModbusCloud while the probe stabilizes.
Want to see how it works?
