The Solution And Application Research Of CANopen Master Based On Windows CE

CAN(Controller Area Network) has been the most dominant field bus which was originally developed by Bosch for use in automobiles, with the characteristics of multi-master accessing, real-time capability, error correction, high noise immunity. CANopen is a standard CAN-based high-layer protocol which is sponsored and maintained by CiA(CAN in Automation). By virtue of its openness and flexibility, CANopen is used wildly in machine building, medical technology, rail vehicles, building automation and maritime application.The kernel features and advantages of CAN, from physical and electrical character, frame format, collision and arbitration to error handling and error confinement are introduced in this paper. Based on modeling research and module analysis, the contents and characteristics of CANopen communication mechanism are analyzed so as to establish a solid foundation for CANopen master design and development. Conforming to the common methods of embedded software design and according to the principle of object-oriented design, we arrange the software architecture properly, setting communication and application apart so that communication module presents as C++ general class which is called by the application clsss. The application class only has to include the communication class file to complete basic CANopen communication function.During the development of CANopen master, we firstly solve the problem of high resolution timer and its multi-use, based on that, we realize the CANopen communication frame and application interfaces. After testing repeatedly, PDO, SDO, SYNC and NMT communication objects transmit and receive correctly. At last, an instance is provided and problems in application are discussed. With an object-oriented design, the CANopen master software implements the basic CANopen communication function, and it is easy to maintain, stable, portable, and could be easily adapted to different PC/IPC-based hardware platforms and used in many kinds of control backgrounds.