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  • New item   Room humidity and temperature transmitter | 0–100 % RH | 0–5 / 0–10 V, RS485 Modbus RTU | 24 V AC/DC | VTS RH+T-SENS-D-MODRTU

    Room humidity and temperature transmitter | 0–100 % RH | 0–5 / 0–10 V, RS485 Modbus RTU | 24 V AC/DC | VTS RH+T-SENS-D-MODRTU

    Code: RH+T-SENS-D-MODRTU
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    Relative humidity and temperature transmitter for VTS ventilation units and BMS. Sends humidity as a 0–5 V or 0–10 V signal, humidity and temperature via RS485 Modbus RTU. 24 V AC/DC supply.

  • Product description

    Humidity and temperature transmitter VTS RH+T-SENS-D-MODRTU

    VTS RH+T-SENS-D-MODRTU is a transmitter with a Sensirion SHT31 element that measures relative humidity and temperature. Humidity range: 0–100 % RH, accuracy: ±2 % RH (0–90 % RH). Outputs: 0–5 / 0–10 V for humidity and RS485 Modbus RTU, supply: 24 V AC/DC.

    Key point:
    One transmitter provides both an analogue humidity signal for a simple controller and digital data for a BMS. Modbus registers also provide temperature (±0.25 °C), so no separate temperature sensor is needed.
    Humidity range
    0–100 % RH
    Accuracy
    ±2 % RH
    Outputs
    0–5 / 0–10 V, Modbus RTU
    Power supply
    24 V AC/DC

    Communication interfaces and integration

    RS485 Modbus RTU Humidity and temperature are read from registers; addresses 1–247, baud rate 2400–19200 bps by DIP switches (up to 115200 by software).
    0–5 V / 0–10 V Analogue relative humidity signal; range selected by DIP switch, load >1 kΩ.
    VTS uPC3 / BMS The manufacturer intends it for VTS units with the uPC3 controller; via Modbus RTU it also connects to other BMS.

    Operating principle

    The transmitter is connected to a 24 V AC/DC supply, an analogue input and/or an RS485 line. DIP switches set the 0–5 or 0–10 V range, Modbus baud rate and the 120 Ω terminator.

    The SHT31 element measures relative humidity and temperature every second. Humidity is output as an analogue signal, both values are available in Modbus registers.

    The controller or BMS regulates ventilation, humidification or dehumidification based on humidity and receives temperature without a separate sensor.

    Why choose the VTS RH+T-SENS-D-MODRTU?
    The transmitter has documented parameters and a Modbus register map, so BMS integration is straightforward. The analogue output also lets it work with a simple controller without Modbus.

    Technical specifications

    Product type Relative humidity and temperature transmitter
    Manufacturer / model VTS RH+T-SENS-D-MODRTU (VTS code 1-2-1205-3013)
    Sensing element Sensirion SHT31
    Humidity range 0–100 % RH, resolution 0.01 % RH
    Humidity accuracy (25 °C) ±2 % RH (0–90 % RH), ±3 % RH in the remaining range
    Hysteresis ±0.8 % RH
    Humidity response time 8 s (airflow >1 m/s)
    Temperature accuracy ±0.25 °C, read via Modbus
    Analogue output 0–5 V or 0–10 V (DIP switch), relative humidity only, load >1 kΩ
    Digital interface RS485 Modbus RTU, addresses 1–247, 2400–19200 bps (up to 115200 by software), parity none/even/odd
    Modbus functions 0x03, 0x06, 0x10
    Line terminator 120 Ω, enabled by DIP switch
    Power supply 24 V DC (20–30 V) or 24 V AC (20–28 V)
    Operating temperature 0…+50 °C, dust-free air and neutral gases
    Housing dimensions 80 × 82 × 55 mm (without probe)
    Connection screw terminals, 5 mm pitch

    Key functions

    • Two outputs – analogue 0–5 / 0–10 V and RS485 Modbus RTU
    • Temperature via Modbus – extra measurement without a separate sensor
    • SHT31 element – ±2 % RH and ±0.25 °C
    • DIP switches – output range, baud rate and terminator without programming
    • Wide choice of Modbus settings – addresses 1–247, parity, stop bits
    • 24 V AC/DC supply – fits standard ventilation controllers

    How does it differ from similar products?

    Sentera RSTHM-2 (22725) Room Modbus sensor with PoM 24 V DC – power and data over one cable.
    Room T/RH sensor with LCD (5272) Has a display and 0–10 V / 4–20 mA, but no Modbus and no confirmed specification.
    Duct RH sensor 0–5 / 0–10 V (3480) Duct humidity sensor with analogue output, Modbus not stated in the name.

    Where is it used?

    • VTS ventilation units with uPC3 controller
    • Offices and meeting rooms
    • Schools and public buildings
    • Warehouses and archives
    • BMS-controlled spaces
    • Plant rooms with ventilation

    Use by need

    For beginners.
    Connect 24 V supply and the analogue output to the controller, select 0–10 V with the DIP switch.
    For experienced installers.
    With RS485, set address and baud rate, enable the terminator only at the line end, connect the shield to PE on the supply side.
    For engineers / designers.
    For BMS integration use the VTS register map: humidity, temperature, status, device ID and software version.

    Practical application

    Situation: an office has a VTS ventilation unit, and the BMS needs humidity and temperature data from the room. Solution: an RH+T-SENS-D-MODRTU is installed and connected to 24 V and the RS485 line. Result: the BMS reads humidity and temperature via Modbus, and ventilation is regulated according to actual room conditions.

    Pros / advantages

    • Analogue and Modbus RTU output in one device
    • Accuracy ±2 % RH and ±0.25 °C
    • Documented Modbus register map
    • Settings via DIP switches
    • Built-in 120 Ω terminator
    • 24 V AC or DC supply

    Cons / limitations

    • Only humidity is sent as an analogue signal – temperature only via Modbus
    • Operating temperature 0…+50 °C – not for cold rooms or outdoor air
    • No IP rating stated – not for damp or aggressive environments
    • No display – for on-site readings choose an LCD version such as the room T/RH sensor with LCD (5272)

    Safety and installation notes

    • ⚡ Supply only 24 V DC (20–30 V) or 24 V AC (20–28 V) – 230 V AC will damage the transmitter.
    • ⚡ Make connections with the supply switched off; installation by a qualified person.
    • RS485: connect RXTX+ to line A, RXTX− to B; enable the 120 Ω terminator only at the line ends.
    • In noisy environments use shielded cable and connect the shield to the nearest PE on the supply side.
    • Use in dust-free air with neutral gases, 0…+50 °C.

    Quick selection guide

    0–100 % RH
    ±2 % RH
    0–5 / 0–10 V + Modbus RTU
    24 V AC/DC
    Suitable when you need:
    • a humidity signal and Modbus data at the same time
    • integration into VTS uPC3 or a BMS
    • temperature via Modbus without a separate sensor
    • a 24 V AC/DC supply
    Check before choosing:
    • whether you need the room or the duct version
    • whether the controller needs 0–5 V or 0–10 V
    • Modbus address and baud rate in your network
    • whether ambient temperature is 0…+50 °C
    Important reminder: The transmitter measures and sends data but has no relay output – the humidifier or fan is controlled by the VTS controller or BMS. Temperature is available only via Modbus.
    ☝ Elsprendimai.eu recommends:

    FAQ

    Does the analogue output carry temperature?
    No. The analogue 0–5 / 0–10 V signal carries relative humidity only. Temperature is read via Modbus RTU.
    How do I choose 0–5 or 0–10 V?
    With a DIP switch. For example, 50 % RH equals 2.5 V (0–5 V) or 5.0 V (0–10 V).
    What are the Modbus settings?
    Addresses 1–247, baud rate 2400–19200 bps by DIP switches or up to 115200 by software, parity none/even/odd, 1 or 2 stop bits.
    What supply voltage is needed?
    24 V DC (20–30 V) or 24 V AC (20–28 V).
    Is it a room or a duct transmitter?
    The VTS e-shop lists code RH+T-SENS-D-MODRTU as a duct transmitter, while the documentation also provides for a room type. Confirm the version before ordering.
    Does it work with non-VTS units?
    Yes, if the controller accepts a 0–5 / 0–10 V signal or Modbus RTU over RS485.

    Sources: VTS HUMID_EN_2.0 documentation, VTS AHU e-shop, VTS HUMID_ROOM_EN. Checked 2026-10-19.

    VTS RH+T-SENS-D-MODRTU humidity and temperature transmitter

    VTS RH+T-SENS-D-MODRTU is a humidity and temperature transmitter with 0–5 / 0–10 V output, RS485 Modbus RTU and 24 V AC/DC supply. It suits VTS ventilation units and BMS systems.

    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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