说明：  解析西门子PP I协议, 便于开发人员研制、开发、集成控制系统, 针对该协议不公开的特点, 在串口通信技术的基础 上, 利用多串口监视的方法捕获协议并借助第三方成熟软件进行对比分析、协议测试。该方法成功地解决了如何获取S7-200 PPI 协 议的问题, 并在C++ Builder开发环境下成功研制了通信控件, 实现了其在测控系统的应用。
(In order to analyze PPI pro tocol to make personnel easily research, develop and integrate the control system, while the PPI protocol of Siemens is not open to the public, on the basis of serial communication, by using method of multiple serial ports monitoring, the protocol has been captured. With the aid of the third party software, the protocol is analyzed and tested. The method successfully resolves the problem of how to capture S7-200 PPI protocol and the commun ication controls have been deve loped under C++ Builder env ironm ent to mi plement its application in m easuring and contro l systems)