基于EPICS的慢速设备异步控制应用研究

针对直线感应加速器控制系统大多数前端设备为带通讯接口的慢速设备的实际情况，采用异步通讯模块Asyn和基于字节的模块StreamDevice相结合的方法实现该类设备在实验物理与工业控制系统（EPICS）架构下的分布式控制。系统中使用的国产或自行研制的设备的命令格式不是SCPI格式，而控制系统常需要在一个I/O命令中写入多个参数（PV），而StreamDevice协议中，多个PV设置无法在一个协议函数中实现。采用EPICS实时数据库的Calcout记录作为多参数输入容器，将多个PV组成一个结构化数组，从而实现多个PV变量的同时设置。同样，针对多参数同时读取的情形，使用waveform记录在一次读入操作中能获取多个PV变量的值。

Applications of asynchronous slow devices control system based on EPICS

For the fact that most of the front-end devices are slow devices with communication port in the control system of Linear Induction Accelerator (LIA), this paper combines synchronous communication module Asyn with StreamDevice module to realize the distributed control of these devices based on the EPICS architecture. The multi-parameter input and output methods are proposed based on SCPI and non-SCPI commands. The command format supported by domestic devices is not SCPI, and it is usually needed to read or write multiple PVs in one I/O command, but the protocol in StreamDevice does not support. In this paper, Calcout record is used to combine several PVs in to a structured array to implement setting multiple PVs at one time, and waveform record is used to implement reading multiple PVs at one time.