Research And Design Of Real-time Industrial Ethernet EtherCAT Master Station

As industrial control system requirement is increasing daily, traditional fieldbus shows more and more problems such as low transfer rate, little transmitted data. On the other hand, computer and high-speed Ethernet communication technology is developing rapidly. A new fieldbus generation using Ethernet technology which is named real-time industrial Ethernet has become hot topics in the research and application of industry in recent years. Among the real-time industrial Ethernet, the real-time industrial Ethernet EtherCAT have attracted much attention because of its excellent features such as high communication speed, real-time performance, flexibility and other technical characteristics. But the EtherCAT technology is mainly monopolized by foreign enterprises and domestic proprietary EtherCAT technology is rare so far.By the analysis of the advantages of industrial Ethernet and features of the EtherCAT technology, and considered of the development in the domestic and overseas, the real-time industrial Ethernet EtherCAT is chosen as the research subject, and this paper is to design the embedded master station based on EtherCAT with Beaglebone development board of Texas Instrument as the hardware platform. Through research and analysis of industrial Ethernet EtherCAT protocol, the content of physical layer, data link layer and application layer of the EtherCAT protocol is introduced, which the FMMU, SyncManager, synchronous mode, COE and other key points of EtherCAT protocol are deeply analyzed.According to the EtherCAT protocol, the architecture of the EtherCAT master station software is decoupled and designed using the UML modeling and analyzing tool, and the software program is implemented. The design idea, the design scheme and the concrete solution of every module of the EtherCAT protocol stack layer and the EtherCAT service layer in the software architecture are given in this paper.In the end of this article gives the verification of the EtherCAT master station solution. A EtherCAT network is built with the designed EtherCAT master station and several servo systems of the Sanyo R-Advanced series servo system with EtherCAT interface. In order to verify the function of the EtherCAT master station, the master station control the servo systems state transferred from initialization state to operation state followed the EtherCAT state machine and analyzing the Ethernet frame by Wireshark through this network. And the master station control the servo systems operation in SYNC Synchronous Mode for purpose of the verification of network synchronization. At last, the network analyzer NetAnalyzer of Hilscher is used to analyze the performance of the EtherCAT master station.