Abstract: In order to improve the operation efficiency and the real-time performance of real-time Ethernet systems, a method that accomplishes the scheduling cooperation between the control and the communication in EPA（Ethernet for Plant Automation） system is proposed. On the base of EPA deterministic scheduling mechanism, EPA-SC method divides EPA macro cycle into two parts: the communication time slice and the control time slice. A timer is set in each EPA device. When the communication time slice or the control time slice comes, the timer will induce an interrupt. While the interrupt handler is implemented, EPA device acquires the current time and determines whether to implement its communication task or to implement its control task according to whether the current time is in the communication time slice or in the control time slice. The experiments prove that the method can effectively avoid the invalid implementation of function blocks and the invalid transmission of data, so that the operation efficiency and the real-time performance of EPA system are improved.

Key words: real-time Ethernet, real-time performance, operation efficiency, control and communication, scheduling , cooperation

摘要： 为了提高实时以太网系统的运行效率和通信实时性，在EPA（Ethernet for Plant Automation）确定性通信调度的基础上，提出了控制与通信的协同调度方法。该方法将EPA设备的通信宏周期划分成通信时间片和控制时间片，在系统中设置定时器，在通信时间片或控制时间片到达时，由定时器引发中断，在执行中断处理程序时获取当前时间，根据当前时间位于通信时间片内或控制时间片内来分别执行通信任务或控制任务。实验结果表明，该方法能够有效避免功能块的无效执行和数据的无效传输，提高系统的运行效率和通信实时性能。

关键词: 实时以太网, 通信实时性, 运行效率, 控制与通信, 协同调度