Modbus is a communication protocol that is widely used in industrial automation and control systems. It provides client/server communication between industrial devices such as PLCs, I/O modules, motor drives, sensors, Industrial Cellular Routers, and actuators.
There are two popular variants of Modbus used in industrial networks – Modbus RTU and Modbus TCP/IP. Both these protocols are used for establishing master-slave communication between industrial devices.
Modbus RTU uses serial communication over RS-485 or RS-232 interfaces. It transfers data in a binary format. Modbus TCP/IP uses Ethernet networks and the TCP/IP protocol stack for Client/Server communication. It encodes data in ASCII format.
In this comprehensive guide, we will take a deep dive into Modbus RTU and Modbus TCP/IP protocols, their functionality, benefits, limitations, and applications. We will also do a comparative analysis of both protocols to understand when to use Modbus RTU and when to adopt Modbus TCP/IP.