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

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