Research On Safe And Real-time Industrial Ethernet

Industrial Ethernet is the application of Ethernet technology in industrial control system. With industrial control system developing towards decentralization, network and intelligence, FiledBus hasn’t satisfied the demand of the industrial control system. However, Ethernet technology, with the advantage of low cost, high speed and good compatibility, is becoming the mainstream technology of the industrial control system. But traditional Ethernet technology adopting CSMA/CD algorithm leads to uncertainty in the communication and can’t meet the requirement of real-time performance in industrial control network. Meanwhile, facing the interference of special circumstance of industry, there will be all kinds of communication errors, but traditional Ethernet technology unable to deal effectively with these errors which may cause serious problems. Hence, real-time performance and safety communication are the main obstacles of the application of Ethernet in industrial control system.This thesis summarizes the research background of industrial Ethernet and the present research from home and abroad firstly. Secondly, it analyses the functional requirement of the real-time performance and safe communication when the Ethernet technology has been applied in the field of industrial control and puts forward a general designing plan of the communication protocol of the safety and real-time industrial Ethernet on these basis.For the demand of real-time performance, this thesis proposes a real-time scheduling mechanism based on time triggering, which assures that there is only one message transmitting in the network at any time, and avoids message conflict and enhances the real-time performance of the whole network. For the demand of safe communication, it extends functional safety transport protocol between real-time scheduling layer and application layer, and safety measures are taken to process and recover the errors when there may be all kinds of communication errors. So the communication safety of network is assured.Finally, the thesis builds a relevant experimental test platform in the lab to test the communication protocol of the safety and real-time industrial Ethernet on real-time scheduling and secure communications. The experimental results demonstrate that the real-time performance and safety performance of the communication protocol have achieved the anticipated goal.