Design and Implementation of Modbus RTU/TCP Protocol Based on Raspberry Pi

With the development of automation technology and computer networks, fieldbus control system has made rapid progress, and many of industrial processes are being controlled by this system. Modbus is one of the most widely used fieldbuses among most users and manufacturers because of its ease of design, low cost, high reliability and flexibility. In this article, Modbus Master/Slave protocol is implemented by using C programming language. The presented system provides usability of Modbus RTU and Modbus TCP both in a single platform. In addition, Linux operation system is used in order to reduce development workload, save time and make any automation application easier to deploy. Hence, in this article Raspberry Pi with Raspbian Jessie OS (Linux kernel-based operating system designed specifically for the Raspberry Pi) is selected as the core of the system. Raspberry Pi is efficient according to its price, speed and documentation. The specification of Modbus protocol and Raspberry Pi are clarified and finally the results of implementation of Modbus function codes are shown. The stability, reliability and excellent performance is confirmed by the results of the system.