The Realization And Research On Real-time Of CANopen Network

Many industrial control systems, such as automatic color register system, usually facethe communication requirements of multiple nodes, a large amount of data, real-time andreliability. However, the traditional serial communication is difficult to meet theserequirements. The CAN bus has been widely appreciated because of its high performanceand unique design. The CANopen protocol is a kind of CAL protocol which is widely used,its features of openness and high-performance make it can meet the requirements ofopenness, interoperability, real-time and reliability in industrial control systems.The independent development of CANopen slave based on DSP were realized in thispaper, including hardware design and software development, and the CANopen network wasbuilt between this slave and the master based on USBCAN-E-P for testing.Firstly, the research and application status of CAN and CANopen were summarized inthis paper, the background and significance of the topic were also introduced. Secondly, theCAN bus and CANopen protocol were introduced and analyzed, the network model andnetwork structure were described, the hardware platform of CANopen network weredesigned. In addition, the software design ideas, the development process, the concreterealization of each software modules and communication functions, the configuration ofDSP, the handling of interrupts, the design of information sending and receiving were alldetailed. The results of communication test and functional verification were also given,which show that the design can achieve the CANopen communication, and the network has acertain degree of reliability and real-time.Finally, from the requirements of multi-nodes and high real-time in industrial networks,the defects of CAN networks were analyzed, and the information scheduling strategies oftime division and priority promotion were researched, the improvement and algorithms inthe application of the above strategies were also provided.