摘要
系统采用SIEMENSS7-2 0 0PLC ,控制纸机的上浆浓度、流量等参数 ,达到间接控制纸页的定量和水分的目的。通过硬件和软件侦听的方法 ,分析PLC内部固有的PPI通讯协议 ,然后上位机采用VB编程 ,遵循PPI通讯协议 ,读写PLC数据 ,实现人机操作任务。这种通讯方法 ,与一般的自由通讯协议相比 ,省略了PLC的通讯程序编写 ,只需编写上位机的通讯程序 ,节省PLC资源 。
The system adopts SIEMENS S7-200 PLC, controls the parameters of paper machine pulp consistency and flow, to indirectly control the base weight and moisture of paper. By means of monitoring of hardware and software, it analyzes the internal PPI communication protocol of PLC, then reads and writes the data of PLC by programming with VB on PC and following with PPI protocol, realizes the Man-Machine operation. Compared with the ordinary free communication protocol, this way omits PLC communication programme, only programmes the communication procedure on PC, saves PLC resources, shortens researching cycle of system.
出处
《计算机测量与控制》
CSCD
2003年第11期884-886,共3页
Computer Measurement &Control
