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The AIO design also supports Modbus thermostats directly connected to the Micro CAN. This enables physical Modbus thermostats to be seamlessly integrated in the Openmotics system and allow users to control their thermostats online, by mobile app and by physical thermostats.

These are the possibilities of the physical thermostat supported by Openmotics:

  • Allows to set the setpoint of a room
  • Allows to change the mode (vacation, auto, party etc)
  • Change between heating and cooling
  • Uses the internal temperature sensor as sensor probe for the Openmotics system

Supported Modbus thermostats

Today, only Openmotics Modbus thermostats are supported but more thermostats will be supported in the future.

How to connect the Modbus thermostat

Following is needed to connect a Modbus thermostat:

  • A installed Micro CAN
  • An Openmotics Modbus cable
  • An Openmotics Modbus thermostat

The Modbus thermostat will be connected to the Openmotics Micro CAN by using the Openmotics Modbus cable that converts the UART output of the Micro CAN to a modbus signal.

The Micro CAN will communicate with the Modbus thermostat and will read the temperature of the thermostat, is able to read and set the thermostat setpoint and read/set the thermostat mode.

How to configure the system after connecting a Modbus Thermostat

ThermostatMode .BIT7: Wait Gateway for Setpoint to be updated (1) .BIT6: Wait Micro CAN for Setpoint to be updated (1) .BIT5: .BIT4: Thermostat responding (1) .BIT3: Mode .BIT2: Mode .BIT1: Cooling (0), Heating (1) .BIT0: Thermostat not in use (0), in use (1)