The method of reading and writing data in PLCs through PPI protocol is specified.Finally,an application example of PPI protocol in papermaking process control system is presented.

• 详细论述了如何利用已解析的PPI协议来读写PLC中的数据,并以某纸厂五叠网纸机的纸浆浓度控制系统为例,说明在纸机控制系统中如何利用PPI协议来进行通讯设计。