Design And Implementation Of Industrial Ethernet EtherCAT IO Slave

With the comprehensive promotion of the strategy of "Made in China 2025",modern advanced manufacturing industry develops rapidly.And the technology of industrial automation improves constantly as well.The motion control system which is networked,intelligent,coadjutant and distributed has shown a strong vitality.However,the traditional fieldbus cannot meet the demand due to its poor compatibility and low speed of communication.At the same time,the industrial Ethernet has been developed rapidly with the advantages of its high real-time performance,good versatility,fast data transmission speed and rich supporting products.The EtherCAT technology developed by Beckhoff is highly favored for its excellent performance.In order to meet the application requirements of industrial Ethernet technology in high-speed and high-precision motion control system for laser cutting machine,this paper designs a slave system with ARM+ESC structure,based on the in-depth study of EtherCAT protocol and working principle.Firstly,the research and development status of Industrial Ethernet and EtherCAT technology were discussed after consulting the literature.And then according to the specific project requirements,the slave system solution was finally determined by comparing the existing solutions.The EtherCAT protocol was studied hierarchically according to its communication model.After that,the modular concept is adopted in the design of the hardware system.The LAN9252 chip is used as the EtherCAT slave controller to implement the physical layer protocol and data link layer protocol.The STM32F407ZGT6 chip developed by STMicroelectronics is used as the EtherCAT slave microcontroller to implement application layer protocol and logic functions.Peripheral circuits,such as power modules,isolated drive modules,differential communication modules,etc.,are designed to support the developed slave systems for practical projects.The slave controller housing is designed and manufactured to support the developed system to be used as a product.Secondly,software is designed and implemented using hierarchical design ideas.The software is divided into initialization module and main loop function moduleaccording to the running process.And the main loop is composed of communication protocol stack,application layer protocol and logic functions.This paper describes the principle and process of the relevant program,and verifies the software program on the developed hardware circuit.Finally,after the design of the system software and hardware,an experimental platform was built to perform a series of systematic verification and testing,such as hardware testing,basic communication testing,basic functional testing,project requirements functional testing,and standard stability testing,etc.The slave station system was successfully applied to the high-speed and high-precision motion control system of GF3015 laser cutting machine and CK leather laser cutting machine.The system passed the long-term running test successfully as well.This paper verifies the feasibility of building a bridge between EtherCAT system and conventional numerical control equipment with the rich peripheral resources of STM32 chip and cost-effective LAN9252 chip.The testing result shows that the designed slave system achieves the established design indicators and lays a solid foundation for further research and application.