Controller area network (CAN) for computer integrated manufacturing systems

Abstract

Communication acts a central role in computer-integrated manufacturing (CIM). The choice of communication system widely determines the capability and productivity of a factory as a whole. Moreover, in the implementation of CIM systems, the costs associated with the interconnection of the individual CIM components are very important. In CIM, communication is largely used to control programmable manufacturing equipment. Here, the time requirements are high, and error-free data transmission is a necessity. Fieldbuses are special form of local area network dedicated to applications in the field of data acquisition and the control of sensors and actuators in machines or on the factory floor. Many fieldbus standards exist in the market today. Each of them has been invented at different periods by different companies and for different purposes. Controller area network (CAN) is one of the most popular fieldbuses. The highest advantages of CAN are its low cost, abundance of silicon technology, and reliability in networking multiple real-time systems. CAN is a multimaster bus topology and has shown to be very efficient medium for error detection and fault tolerance. CAN's technical specifications are defined in the ISO/OSI network layer spans just two layer of the model. CAN specifies, in many innovative ways, the physical signaling over the media, data formats, timing, error recovery, protocols and arbitration. It does not define the media itself and its connectors, and also the upper layers (usually software) of the model.