Implementing Modbus and CAN Bus Protocol Conversion Interface

Abstract

In communication system design, a key challenge is the ability to make different components from different manufactures communicates with each other. In communication system design, a key challenge is the ability to make different components from different manufactures communicates with each other. A number of field buses are available to exchange the serial data among one or more controllers and a number of field devices that are communicating with each other. However, fieldbus standards are currently not uniform, which brings many difficulties in system design, as different equipment from different manufacturers follow different standards. For a reliable system design, there is a need of efficient communication interface to make the communication possible. Many serial communication protocols like RS-232/RS-485, I2C, SPI, Modbus and CAN bus, etc., were used in embedded systems. All these protocols have their own advantages and limitations. Generally, different manufactures follow different protocols and standards. This makes the system integration task very difficult. Hence, there must be several means to make this task easier. Protocol conversion interface is one of the possible solutions for this problem. CAN bus and Modbus are two most common fieldbus protocol used in industrial control systems. This chapter implements a CAN bus to Modbus protocol conversion interface and investigates the feasibility of such interface in meeting the communication requirements of system.