Design Of Industrial Ethernet Slave Control System Based On EtherCAT

At present,the rapid development of servo technology,and the integration of Ethernet technology into the servo motion control technology have become the current development trend.EtherCAT is a combination of real time Ethernet and field bus,taking the advantage of flexible topology,real time availability,good stability and short refresh cycle,which is very suitable for application in servo drive system.This paper focused on implementing an EtherCAT type interface to connect common servo motors into control network with TCP/IP technology that based on the research of real-time industrial Ethernet and servo drive system.An architecture is presented which uses a Microchip PIC24HJ129GP506 as the slave controller and adopts Mitsubishi AC servo motor and driver as the controlled object prototype,focusing on the control system from the station to the research and design,and ultimately an EtherCAT real-time Ethernet communication servo control system is build.The main work is as following:First,a slave control board is designed using the FB1111-0141 back load controller from Beckhoff.In detail,the physical layer chip used is KS8721 from Micrel company,the data link layer chip used is ET1100 from Beckhoff,and the application layer chip is PIC24HJ128GP506 from Microchip.In addition,the interface circuit of servo system and peripheral interface circuit of all kinds of chips are analyzed and designed.The system is designed with the function of EtherCAT real time Ethernet communication.Secondly,two parts of the system software design are discussed.Firstly,TwinCAT2 is chosen as the master PC software.The slave network interface program can achieve EtherCAT communication between the master and slave,through a series of configuration and the design of ESI(slave description file),which is the base of later application-layer control tasks and communications features.Secondly,the slave application program is coded with PIC microcontroller development environment in MPLAP IDE,which can achieve application-layer control tasks.Finally,the EtherCAT-able servo control system platform is set up based on the prior master and slave hardware and software design.The master and slave communication feasibility experiments and servo motor control experiment are completed and results are shown.The conclusion is that the provided method is available to build an EtherCAT control network for devices without Ethernet interface.