基于EtherCAT的软PLC系统设计与实现

Design and Implementation of Soft PLC System Based on EtherCAT

针对软PLC系统难以实现实时运动控制的问题,基于EtherCAT实时以太网设计一种软PLC系统。在x86架构处理器的PC上搭建Linux+Xenomai双内核实时系统,并基于开源主站协议栈IgH构建可对从站进行实时控制和同步控制的EtherCAT主站;基于EtherCAT实时控制框架设计软PLC系统,根据IEC61131-3编程标准设计ST结构化编程语言的解析模块和运行模块,遵循PLCopen规范开发了运动控制功能块接口,并在大型浴缸自动喷涂生产线上进行IO控制和伺服电机实时运动控制实验。结果表明:基于EtherCAT实时以太网的软PLC系统实时性满足要求,能准确完成IO控制和伺服电机实时运动控制。

Aiming at the problem that soft PLC system is difficult to realize real-time motion control,a soft PLC system based on EtherCAT real-time Ethernet was designed.A Linux+Xenomai dual-core real-time system was built on PC with x86 architecture processor,and an EtherCAT master station was built based on the open source master station protocol stack IgH,which could control the slave station in real-time and synchronically.The soft PLC system was designed based on EtherCAT real-time control framework,the analysis module and operation module of ST structured programming language were designed according to IEC61131-3 programming standard,and the motion control function block interface was developed according to PLCopen specification.Experiments of IO control and servo motor real-time motion control were carried out on a large bathtub automatic spray production line.The results show that the real-time performance of soft PLC system based on EtherCAT real-time Ethernet meets the requirements,and it can accurately complete IO control and real-time motion control of servo motor.