Sentera RCMFF-3
Room sensor for CO2, temperature and humidity that controls ventilation through its output.
The Sentera RCMFF-3 is a room sensor that measures CO2, temperature, relative humidity and ambient light and controls ventilation through one analogue output. This Modbus RTU template reads CO2, temperature, humidity, dew point and alarm flags and lets you set CO2 alert levels and override the output from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 56, read and write
- Brand
- Sentera
- Key readings
- CO2 concentration · Temperature · Relative humidity · Dew point · Ambient light · Output value · Sensor alarms
- Available commands
- CO2 alert levels · CO2 range for the output · Output override · Sensor selection · LED settings
- Compatible models
- RCMFF-3 · RCMFG-3 · RCMFH-3
- Last updated
Registers (56)
56 read, 32 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| CO2 Level | ppm | Read | |||
| Temperature | °C | Read | |||
| Relative Humidity | %RH | Read | |||
| Dew Point | °C | Read | |||
| Ambient Light | lux | Read | |||
| Active Standby State | Read | ||||
| Actual Output Value | % | Read | |||
| Output Control Mode | Read | ||||
| Temperature Output Value | % | Read | |||
| Humidity Output Value | % | Read | |||
| CO2 Output Value | % | Read | |||
| CO2 Alert 1 | Read | ||||
| CO2 Alert 2 | Read | ||||
| CO2 Sensor State | Read | ||||
| Temperature Alert Flag | Read | ||||
| Temperature Range Limit Flag | Read | ||||
| Temperature Sensor State | Read | ||||
| Humidity Alert Flag | Read | ||||
| Humidity Range Limit Flag | Read | ||||
| Humidity Sensor State | Read | ||||
| Ambient Light Sensor State | Read | ||||
| CO2 Alert 1 Level | ppm | Read and write | |||
| CO2 Alert 2 Level | ppm | Read and write | |||
| Minimum CO2 Range | ppm | Read and write | |||
| Maximum CO2 Range | ppm | Read and write | |||
| CO2 Self Calibration | Read and write | ||||
| Minimum Temperature Alert | °C | Read and write | |||
| Maximum Temperature Alert | °C | Read and write | |||
| Minimum Humidity Alert | %RH | Read and write | |||
| Maximum Humidity Alert | %RH | Read and write | |||
| Minimum Temperature Range | °C | Read and write | |||
| Maximum Temperature Range | °C | Read and write | |||
| Minimum Humidity Range | %RH | Read and write | |||
| Maximum Humidity Range | %RH | Read and write | |||
| Active Light Level | lux | Read and write | |||
| Standby Light Level | lux | Read and write | |||
| Output 1 Mode | Read and write | ||||
| Output 1 Overwrite Enable | Read and write | ||||
| Output 1 Overwrite Value | % | Read and write | |||
| Output 1 PWM Voltage Source | Read and write | ||||
| Output 1 Minimum | % | Read and write | |||
| Output 1 Maximum | % | Read and write | |||
| Temperature Sensor Selection | Read and write | ||||
| Humidity Sensor Selection | Read and write | ||||
| CO2 Sensor Selection | Read and write | ||||
| LED Indication | Read and write | ||||
| LED Brightness | % | Read and write | |||
| Modbus Address | Read and write | ||||
| Modbus Baud Rate | Read and write | ||||
| Modbus Parity | Read and write | ||||
| Modbus Safety Timeout | min | Read and write | |||
| Network Termination | Read and write | ||||
| Modbus Registers Reset | Read and write | ||||
| Device Type | Read | ||||
| Hardware Version | Read | ||||
| Firmware Version | 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 CO2, temperature and humidity per room on a ModbusCloud dashboard.
- Get an email when CO2 alert 2 is active for a classroom or meeting room.
- Keep 365 days of CO2 history to show indoor air quality over the seasons.
- Raise or lower the CO2 alert levels remotely when the use of a room changes.
- Override the fan output from the portal during commissioning and hand it back to the sensor afterwards.
Installation
Connect 24 V supply, A and B to the sensor and run the RS485 bus to the ModbusCloud Gateway.
Switch on the built-in termination on the last device of the line and terminate the other end at the Gateway.
Give every Sentera device on the bus its own address; the factory default is address 1 at 19200 baud, 8E1.
In ModbusCloud, add a Modbus device with that address and settings and import the Sentera RCMFF-3 template.
Check that CO2, temperature and humidity match the room; CO2 in an empty, aired room is close to outside level.
Things to watch for
The sensor does not answer on the bus. What should I check?
Check the supply, A and B, and that address, baud rate and parity in ModbusCloud match the sensor. The factory setting is address 1, 19200 baud, 8E1. New Sentera devices all start at address 1, so connect them one at a time and give each its own address first.
Why does the CO2 value drift over time?
With self calibration on, the sensor takes the lowest level of the past days as outside air. In a room that never airs out, that lowers the readings. Switch self calibration off in such rooms, or make sure the room reaches outside air level at least once a week.
The output does not follow the value I write. Why?
The override value only works when output override is enabled. Set the enable register to 1 first, then write the value, and set it back to 0 afterwards. When the Modbus safety timeout runs out without traffic, the output goes to its minimum.
What should I watch out for when writing settings?
A new address, baud rate or parity takes effect on the sensor, so update the Modbus device in ModbusCloud right after. Writing 1 to the register reset restores all holding registers above 10 to their defaults, including CO2 levels and output settings.
More Sentera templates
Want to see how it works?
