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  • New item   -149.01€Multifunction CO2 room transmitter | CO2 400-2000ppm | T 0…50°C | 0-95%rH | 3×0-10VDC/0-20mA/PWM | Modbus RTU | 24VDC | IP30 | Sentera Controls | RSMFF-3
    New item   -149.01€Multifunction CO2 room transmitter | CO2 400-2000ppm | T 0…50°C | 0-95%rH | 3×0-10VDC/0-20mA/PWM | Modbus RTU | 24VDC | IP30 | Sentera Controls | RSMFF-3 1
    New item   -149.01€Multifunction CO2 room transmitter | CO2 400-2000ppm | T 0…50°C | 0-95%rH | 3×0-10VDC/0-20mA/PWM | Modbus RTU | 24VDC | IP30 | Sentera Controls | RSMFF-3 2
    New item   -149.01€Multifunction CO2 room transmitter | CO2 400-2000ppm | T 0…50°C | 0-95%rH | 3×0-10VDC/0-20mA/PWM | Modbus RTU | 24VDC | IP30 | Sentera Controls | RSMFF-3 3
    New item   -149.01€Multifunction CO2 room transmitter | CO2 400-2000ppm | T 0…50°C | 0-95%rH | 3×0-10VDC/0-20mA/PWM | Modbus RTU | 24VDC | IP30 | Sentera Controls | RSMFF-3 4
    New item   -149.01€Multifunction CO2 room transmitter | CO2 400-2000ppm | T 0…50°C | 0-95%rH | 3×0-10VDC/0-20mA/PWM | Modbus RTU | 24VDC | IP30 | Sentera Controls | RSMFF-3 5

    Multifunction CO2 room transmitter | CO2 400-2000ppm | T 0…50°C | 0-95%rH | 3×0-10VDC/0-20mA/PWM | Modbus RTU | 24VDC | IP30 | Sentera Controls | RSMFF-3

    Code: RSMFF-3
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  • Product description

    Multifunction CO2 room transmitter | CO2 400-2000ppm | T 0…50°C | 0-95%rH | 3×0-10VDC/0-20mA/PWM | Modbus RTU | 24VDC | IP30 | Sentera Controls | RSMFF-3

    The RSMFF-3 is a Sentera Controls multifunction CO2 room transmitter that measures CO2 concentration (400–2000 ppm), temperature (0…+50 °C) and relative humidity (0–95 % rH) in a room and has three analog / modulating outputs – AO1 for temperature, AO2 for humidity, AO3 for CO2 (0-10 VDC, 0-20 mA or PWM). Power supply – 24 VDC.

    Key idea:
    Three air quality indicators – three separate signals: the controller or BMS receives CO2, temperature and humidity separately and decides for itself how to control ventilation, heating or humidification. One device instead of three sensors.
    CO2 range
    400–2000 ppm
    Output
    3 × 0-10 VDC / 0-20 mA / PWM
    Power supply
    24 VDC
    Protection
    IP30, indoors only

    Operating principle

    The device is wall-mounted in the room (2 holes Ø 6 mm), in the occupied zone, away from doors, windows and direct exhalation. Connect the 24 VDC power supply (VIN, GND), outputs AO1–AO3 with their own GND, and Modbus RTU (A, /B); the terminals are push-in, for wires up to 1.5 mm².

    A self-calibrating CO2 sensor together with a temperature and humidity sensor measures air quality: AO1 outputs temperature, AO2 – relative humidity, AO3 – CO2. Output type – 0-10 VDC (≥ 50 kΩ), 0-20 mA (≤ 500 Ω) or PWM 1 kHz (3.3 or 12 VDC); all parameters are accessible via Modbus RTU, which is also used to update the firmware.

    Result – the controller or BMS receives CO2, temperature and humidity as separate signals and ventilates according to the actual number of people: in an empty room ventilation runs at a minimum, and as people gather it increases, which reduces heating / cooling losses and fan energy consumption.

    Benefits RSMFF-3?
    Three measurements and three separate signals in one room device – fewer sensors, cables and installation work.

    Technical specifications

    Product type Multifunction CO2 room transmitter
    Manufacturer / code Sentera Controls / RSMFF-3
    Measured quantities CO2, temperature, relative humidity, ambient light level
    CO2 range 400–2000 ppm (accuracy specified up to 5000 ppm)
    Temperature range 0…+50 °C
    Humidity range 0–95 % rH, non-condensing
    Accuracy ±0.5 °C; ±6 % rH; CO2 ±(50 ppm + 3 % of reading) 400–2000 ppm, ±(40 ppm + 5 % of reading) 2001–5000 ppm
    Outputs AO1 – T, AO2 – rH, AO3 – CO2: 0-10 VDC (RL ≥ 50 kΩ) / 0-20 mA (RL ≤ 500 Ω) / PWM 1 kHz, 3.3 or 12 VDC
    Communication Modbus RTU (RS485); firmware update via Modbus RTU
    Supply voltage 24 VDC
    Max. current (Imax) 80 mA
    Indication Red / yellow / green LED with adjustable brightness, ambient light sensor
    Installation On a wall, 2 holes Ø 6 mm
    Protection class IP30 (EN 60529), indoor use only
    Weight 0.095 kg (net)
    Compliance LVD 2014/35/EU, EMC 2014/30/EU, WEEE 2012/19/EU, RoHS 2011/65/EU

    Manufacturer documentation

    ✔ Recommended by Elektrotechnikos sprendimai

    Original manufacturer documentation – technical data, wiring diagrams and installation instructions.

    Main functions

    • Three separate outputs – T, rH and CO2 – each with its own signal to the controller or BMS.
    • Modbus RTU – all measurements and settings are accessible remotely.
    • Firmware update – over the Modbus RTU network.
    • LED indication – green – air quality is good, yellow – warning level 1 reached, red – level 2 or value out of range.
    • Light sensor – adjustable “active” and “standby” illumination levels.
    • SenteraWeb – via a Sentera internet gateway – remote monitoring, log, notifications, mode schedules.
    • Configuration – Configuration and monitoring – the free Sentera 3SModbus software (via the CNVT-USB-RS485 converter) or the Sensistant Modbus configurator.

    Where is it used?

    • Offices, meeting rooms, classrooms
    • Kindergartens, schools, auditoriums
    • Residential rooms and apartments
    • Restaurants, gyms
    • Demand-controlled ventilation with EC fans
    • BMS and SenteraWeb systems

    On-demand operation

    For school ventilation designers.
    A single wall-mounted device in the classroom provides three separate T, rH and CO2 signals to the ventilation controller.
    For the BMS integrator.
    CO2, temperature and humidity are available both as analog signals and over Modbus RTU, and SenteraWeb allows remote monitoring.
    For the installer of 24 VDC control panels.
    The -F version is powered at 24 VDC and wired with 4 wires with separate grounds.

    Practical application

    If a classroom ventilation controller has three 0-10 VDC inputs and the air volume has to be increased as CO2 rises, then the RSMFF-3 is connected to 24 VDC, and AO3 passes CO2 (400–2000 ppm), AO1 temperature and AO2 humidity as separate signals.

    Application guide: how it is used in practice

    The same RSMFF-3 adapts to different sites – only what is connected to its outputs changes:

    Site What is connected Result Installer's note
    Air handling unit with a controller AO3 (CO2) → controller input, AO1 (T) → heating control The controller regulates airflow according to CO2 and temperature Select the signal type according to the controller input
    Simple DCV AO3 (CO2) 0-10 VDC → EC fan Fan speed proportional to CO2 AO1, AO2 can be used for monitoring
    Building with BMS Modbus RTU → A, B All three quantities in the BMS without analog cables A separate address for each device
    Remote monitoring Modbus RTU → Sentera internet gateway → SenteraWeb Data log, alerts, schedules A Sentera internet gateway is required

    How to choose a CO2 transmitter

    Installation / output / power supply Recommended model
    Room, 3 separate outputs T / rH / CO2, 24 VDC, 4 wires RSMFF-3 (multifunction transmitter, -F) ← this model
    Room, 3 separate outputs T / rH / CO2, 24 VDC or 24 VAC, 3 wires RSMFG-3 (multifunction transmitter, -G)
    Room, 1 control output based on T / rH / CO2, 24 VDC RCMFF-3 (smart sensor, -F)
    Room, 1 control output, 24 VDC or 24 VAC RCMFG-3 (smart sensor, -G)
    Flush-mounted / surface-mounted, 1 output, powered from the 230 V mains FCMF8-R (85–264 VAC)
    Flush-mounted / surface-mounted, 1 output, 24 VDC or 24 VAC FCMFG-R (24 VAC/VDC)
    Duct, 1 control output based on T / rH / CO2, 24 VAC/VDC DCMFG-2R (smart duct sensor)
    Duct, NDIR CO2 + T + rH, Modbus RTU only DSCDG0-4 (no analog outputs)
    Duct, NDIR CO2 + T + rH, 3 analog outputs + Modbus RTU DSCDG3-4 (3 outputs)
    Rule: by installation location (wall, flush-mounting box, duct) and by what is needed: separate T / rH / CO2 signals for a controller or BMS (transmitter, 3 outputs), a single control signal directly to an EC fan or damper (smart sensor), or Modbus data only. Choose the supply according to the site's control circuit: -F – 24 VDC, 4-wire; -G – 24 VAC or 24 VDC, 3-wire; 8 – directly from the 230 V mains.
    When to choose another solution: for a single control signal without a separate controller – RCMF-3 series; for flush mounting – FCMF8-R / FCMFG-R; for a duct – DSCDG3-4; without CO2 – RSTH-3 series.

    Pros

    • CO2, temperature and humidity in one device
    • Modbus RTU, firmware updated over the network
    • Three separate outputs T / rH / CO2
    • Self-calibrating CO2 sensor, LED with adjustable brightness
    • Compact wall-mounted housing

    Cons / limitations

    • CO2 measuring range 400–2000 ppm – intended for indoor air quality, not for industrial gas monitoring
    • IP30 – dry rooms only
    • The -F version is not suitable for 3-wire systems or AC supply

    Safety and installation notes

    • Installation and connection are to be carried out by a qualified electrician / automation specialist with the power disconnected.
    • Supply voltage – 24 VDC.
    • The -F version: 4-wire connection, separate supply and analog output grounds – not suitable for 3-wire systems and must never be connected to an alternating current (AC) supply.
    • Do not mix -F and -G type products on the same network.
    • Resetting the Modbus communication parameters – with a jumper on PROG pins 1 and 2 for at least 5 s.
    • For indoor use only; do not install in direct sunlight.

    Quick selection guide

    CO2 400–2000 ppm
    0…+50 °C
    0–95 % rH
    3 × 0-10 VDC / 0-20 mA / PWM
    24 VDC
    IP30
    Suitable when you need:
    • to implement demand-controlled ventilation by CO2 level;
    • to pass CO2, temperature and humidity to a controller or BMS;
    • to integrate air quality data into a BMS via Modbus RTU.
    Check before use:
    • the input type of the controlled device;
    • the supply: 24 VDC;
    • the installation location – an occupied zone, not near doors or windows.
    Important reminder: The RSMFF-3 measures CO2 to assess indoor air quality; it is not a gas leak or safety detector.

    FAQ

    Does it measure VOC?
    No, CO2, temperature, relative humidity and ambient light are measured.
    What are the output signals?
    Each of the three outputs – 0-10 VDC, 0-20 mA or PWM, plus Modbus RTU.
    How are the settings changed?
    Via Modbus RTU – the 3SModbus software with a CNVT-USB-RS485 converter, or via BMS.
    How do I reset the Modbus settings?
    With a jumper on PROG contacts 1 and 2 for at least 5 seconds.
    Does the transmitter control the fan itself?
    No, it passes separate T, rH and CO2 signals to the controller; for direct control choose RCMFF-3.
    What power supply does it operate from?
    24 VDC.

    Multifunction CO2 room transmitter | CO2 400-2000ppm | T 0…50°C | 0-95%rH | 3×0-10VDC/0-20mA/PWM | Modbus RTU | 24VDC | IP30 | Sentera Controls | RSMFF-3

    Sentera RSMFF-3 – multifunction CO2 room transmitter: CO2 400–2000 ppm, temperature 0…+50 °C, humidity 0–95 % rH, three 0-10 VDC / 0-20 mA / PWM outputs and Modbus RTU, 24 VDC supply. For demand-controlled ventilation.

    Illustrative image may have been created using AI. The appearance of the product may differ slightly from the image shown. Please refer to the technical specification.

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