Modbus

The Modbus protocol was originally developed in the late 1970s as a serial communication protocol. The main objectives were to provide a communication protocol for industrial applications that was easy to set up and maintain and transfers data without the need to develop an information model. Because of this simplicity, it has been very popular for 30 years. But this simplicity makes it difficult to use Modbus in modern industrial plants that place more complex demands on a communication protocol, such as security and information models. The original Modbus protocol does not include security measures such as encryption or authentication.

Even though Beckhoff provides two TwinCAT functions for Modbus RTU and Modbus TCP, it is advisable to use more advanced protocols such as OPC UA, which inherently implement security mechanisms.