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)

Setup

Open Settings → Expose devices and select Add Interface. Select Modbus RTU, Modbus ASCII or Modbus TCP.
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)
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:

NModbus4 - C# implementation of the Modbus protocol GitHub
libmodbus - A Modbus library for Linux, Mac OS X, FreeBSD, QNX and Windows GitHub
pymodbus - A full modbus protocol written in python GitHub
digitalpetri / modbus - High-performance, non-blocking, zero-buffer-copying Modbus for Java GitHub
goburrow / modbus - Fault-tolerant implementation of modbus protocol in Go (golang) GitHub
node-modbus-tcp- NodeJS Modbus TCP/IP (GitHub)

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