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Modulating Modbus Room and FCU Controllers | HLS44 Advanced Multifunctional Modbus Room Controller

HLS44 is an advanced multi-functional controller specifically designed for individual room temperature and zone control applications. The controller has built-in Modbus RS-485 communication that allows it to be connected to most BMS systems including SyxthSense FDX solution.

The controller can be used for heating and cooling control, fan speed control and VAV control. Typical applications include 4-pipe fan coil unit control, VAV (Variable Air Volume) control, chilled beam and zone heating control. The controller can control 3-speed fans and has also built-in control logic for modern EC fans that allow 0..100% modulation of the fan speed.

The controller has large range of advance functionality that allows intelligent, energy efficient control with very good comfort function. For example, the fan speed operation at the setpoint is highly adjustable and the controller can remember the users preferred setpoint from previous day, or alternative the setpoint can be set over the Modbus to a more energy efficent system setpoint automatically. Similar functionality applies to fan speed control.

The controller has built-in temperature sensor, or external temperature sensor can be used. The users can adjust the setpoints and fan speed via the built-in touch buttons. Twi digital inputs allow control using occupancy (PIR) sensors, hotel door cards, window/door switches or condensation sensors in chilled beam applications.

In addition analogue input can be used to boost the ventilation when the indoor air quality deteoriates (CO2 measurement).


  • Wall mounted, LCD display, touch buttons for settings, built-in sensor
  • External temperature sensor option
  • 4 AOs (0..10Vdc) for VAV damper, Fan Speed, Heating and Cooling Actuators
  • 2 24Vac Triacs for Heating and Cooling Actuators
  • 1 Digital Input for Day/Night Mode Control
  • 1 Digital/Universal Input for door window contact or external sensor
  • 1 0..10Vdc Input for External setpoint or for CO2 measurement
  • Supports modern EC Fans (seamless fan speed control)
  • Modbus RS485 RTU Communications
  • Networkable to most BMS and SyxthSense FDX Solution
  • Unused IOs can be used as Modbus IOs
  • Advanced application functionality
  • Configuration via built-in configuration mode
  • Night and Day Operation Modes
  • Relaxed Setpoint at Night or Off-Mode with Frost Protection at Night
  • LED displaying the current heating or cooling mode

Application Example - 4-Pipe Fan Coil Unit Control With Fan Speed:-

HLS44 4-Pipe Fan Coil Unit Controller with Fan Speed

Application Example - Chilled Beam with Zone Heating:-

Chilled Beam and Zone Heating Control

Application Example - Cooling with Chilled Beam and VAV, Zone Heating:-

Chilled Beam and VAV Control, Zone Heating