关键词: EPA, 实时以太网, 控制, 通信, 同步

Abstract: In order to improve the real-time performance of EPA (Ethernet for Plant Automation) system, EPA-CCS (EPA Control and Communication Synchronization) method that accomplishes the synchronization between control and communication in EPA system is proposed. On the base of EPA deterministic scheduling mechanism, EPA-CCS method divides EPA macro cycle into two parts: communication time slice and control time slice. EPA device acquires the current time during its each round scan 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. When the control task is implemented, EPA device ensures the function blocks can be implemented only once in a macro cycle through setting and scanning state signs. An experiment proves that this method can effectively avoid the invalid executions 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:

Ethernet for plant automation (EPA), real-time Ethernet, control, communication; synchronization