Research And Simulation Of Industrial Ethernet EtherCAT For Communication System

With the background of using Industrial Ethernet in the train communication system for monitoring and fault detection, EtherCAT slave station device is designed and researched, and EtherCAT protocol is modeled and simulated. It can provide technical reference for using EtherCAT in the train communication system.Firstly, EtherCAT communication network environment is established. TwinCAT configuration for EtherCAT is briefly analyzed,and it can provide the environment for the further research.Next, based on EtherCAT slave chip and protocols, inteligent EtherCAT slave station is implemented on embedded Linux systems. Hardware interface and configuration of other functional modules are designed for the final hardware circuit board. Ethernet sub-packet transmission in the EtherCAT network segment is achieved based on EOE protocol after Linux system being tailored and slave netcard driver being developed. Boa web server in EtherCAT slave station is established for testing the network performance.Then, EtherCAT clock synchronization error model is established, and clock synchronization algorithm and error simulation program are designed. Based on three basic topology structure of EtherCAT, simulation and analysis of the synchronization error is done, after that, the formulae and parameter of the synchronization error accumulation for each kind of topology are summarized. Accumulation formulae provide theoretical reference for building complex topologies in practical application, and they can be used to improve the clock synchronization algorithm in master station.Finaly, after analyzing and comparising the pros and cons of the EtherCAT protocol, a new protocol named EtherDOG based on EtherCAT is proposed, it can realize functions such as communicating without master, master election, parallel transmission, addressing by topology and so on. Modeling and simulation of EtherDOG is done for feasibility study. EtherDOG protocol can provide communication technical support for Self-Organization, Self-Adaptive, Modulization of micro-segments and so on.