The Analysis And Implementation Of The CANopen Slave Node Based On RT-thread

With the high speed development of the fieldbus technology,the CANbus has become an essential part in the industrial development.Based on the CANbus,the application layer protocol-CANopen has played an important role not only in the core industry such as the aerospace industry and the marine or the automotive or medical fields,but also in some ares which are related to people’s daily life such as the elevator system just for its high stability and anti-interference.The focus of this paper is trying to analyse the principle of the CANopen protocol and implement it under the RT-thread.Firstly,this paper introduces the background and the development process of the CANopen protocol.Then the advantages of this application layer protocol are narrated.What’s more,the basic frame of the RT-thread operation system is shown.In this part,the article mainly studies the fundamental functions of these core modules in the micro kernel:memory management module,thread scheduling, thread management, etc.After the declaration of a concept that all devices in the CANopen can be viewed as a set of some objects,this article explained the device module of the CANopen and the meaning of the object dictionary.Then the operation mode and principle of some crucial objects of the CANopen protocol are studied.What’s more,the application scope of the service data object is declared and the analyzation of the whole process of these different communication services is done.Lastly,a set of CANopen protocols are implemented under the C language.In order to verify whether these protocols meet the requirements,a set of experiments are done on different modules such as NMT control module,SDO communication module and so on.As the results shown,these protocols can work normally under some data communication tests.