ISA/IEC 62443 Cybersecurity Fundamentals Specialist (IC32) Practice Test

The TCP port number used by Modbus is 502. Modbus is a widely used communication protocol in industrial automation systems. It is designed for transmitting data between devices over networks and is commonly used in scenarios involving programmable logic controllers (PLCs) and other industrial equipment. The choice of port number 502 is a standardized designation, which allows devices that implement the Modbus protocol to recognize and communicate effectively with each other on a network.

The defined usage of port 502 is important because it ensures interoperability among various manufacturers' devices, leading to consistent communication within control systems. By adhering to this standard, users can configure their industrial control systems with confidence that devices adhering to the Modbus protocol will communicate seamlessly, thereby facilitating consistent data exchange and system reliability.