TapHome to Modbus RTU / ASCII / TCP

Supported communication layers

  • Modbus RTU via RS485 (BUS 1, BUS 2, or BUS 3 terminals)
  • Modbus ASCII via RS485 (BUS 1, BUS 2, or BUS 3 terminals)
  • Modbus TCP (via ethernet, connecting to local IP address or VPN)


  1. Open Settings → Expose devices and select Add Interface. Select Modbus RTU, Modbus ASCII or Modbus TCP.
  2. Define communication properties
    • 2.1 Modbus RTU or ASCII: Terminal (BUS 1, BUS 2 or BUS 3), Baud rate, Parity, Data bits, Stop bits
    • 2.2 Modbus TCP: TCP Port. (IP Address is set specifically for every device)
  3. Add devices to be exposed
    • Each device will show brief overview how to access them in 3rd party system

Example: Switch:

Using Modbus TCP to connect to any other system

Simply Modbus ( is a great source if you are unfamiliar with the protocol. Using open source libraries for Modbus, you can connect TapHome installation with any other system that has possibility to develop a simple driver:

Debugging Modbus RTU connection

Modbus RTU is using RS485 physical layer. In order to speed up your integration, please consider parallel connection of RS485 USB converter to your PC in order to see communication.

Standard USB to RS485 converter:

Terminal software for Windows: