Design And Implementation Of EtherCAT Communication Protocol Stack For Zynq Embedded Platform

With the development of industrial Internet of Things technology,the manufacturing industry's requirements for fieldbuses are also increasing.The past fieldbuses can no longer meet the needs of today's manufacturing industry.The EtherCAT protocol,which inherits the advantages of Ethernet,has become one of the research hotspots of industrial Internet of Things..However,the current EtherCAT protocol stack is mainly implemented on the PC platform,which has disadvantages such as large size and difficult deployment.Therefore,this article designs and implements the EtherCAT communication protocol stack on the Zynq embedded platform.While making full use of the advantages of the embedded platform's small size,easy deployment and good stability,it meets the performance requirements of the industrial fieldbus.In order to facilitate the writing and running of the protocol stack software,this article uses Xilinx's official Peta Linux tool to transplant the Linux operating system on the Zynq embedded platform,and then installs the RT-PREEMPT real-time kernel patch for Linux to improve the real-time performance of the operating system.In order to improve the real-time performance and security of the protocol stack,this paper designs the network adaptation unit of the EtherCAT protocol stack on FPGA,and adds the security function at the same time.In order to enable the protocol stack to call the network adaptation unit normally and reduce the storage resources occupied by the protocol stack,this article refers to the open source framework for tailoring and modification,through the state machine module of the EtherCAT protocol stack,the DC distributed clock module,and the fieldbus memory management unit The design and implementation of the FMMU module,the periodic process data communication module,the mailbox data communication module and the underlying data transceiver module constructed the protocol stack architecture,completed the software and configuration of the protocol stack,and completed the design and implementation of the EtherCAT protocol stack.Through testing on the experimental platform built in the laboratory,the EtherCAT protocol stack based on the Zynq embedded platform designed in this paper has good real-time performance.When the protocol stack software fails,the security function runs normally,the various states of the protocol stack transition smoothly,the data frame transmission function is correct,and the period jitter is small,which basically meets the requirements of the EtherCAT protocol stack in the industrial control field.