提高EPA系统网络时延性能的方法

为了提高EPA(Ethernet for plant automation)系统的网络诱导时延性能，研究了系统中功能执行和网络通信的内在运行机理和相互作用机制，提出了它们的协同方法。该方法通过给执行控制功能的用户层功能块和执行通信功能的链路层分组传输设定相互协同的时间片，以及对功能块执行时间和次数的确定，实现了EPA系统中控制与通信的协同。当设备巡回扫描周期较小或需要通信的功能块较多时，能够有效降低EPA系统的网络负载，提高网络诱导时延性能。

Method to improve the performance of network time delay of EPA system

In order to improve the performance of network-induced time delay of EPA (Ethernet for plant automation) networked control systems, the interacting mechanism between the control and the communication in EPA system was studied and EPA-CS (EPA cooperative scheduling) method was presented. Through setting their mutually cooperative time slices for function blocks that executed the control tasks and data transmission that executed the communication tasks, and through determining the executing time and frequencies of control tasks in their time slices, the method could accomplish the cooperation between control tasks and communication tasks in EPA system. When the round scanning cycles of devices are very little or there are many function blocks that need network communication in system, the method can effectively reduce the network load to improve the performance of network-induced time delay of EPA system.