计算机控制系统在峨山化肥厂干冰生产线中的应用

干冰生产过程自动监控是基于PLC的集散式控制系统；系统由上位计算机和PLC组成，对生产过程进行全程控制和管理；上位计算机通过监控画面对PLC进行参数设置，接受参数后PLC执行闭环控制；使用Citect组态软件设计各种监控画面；计算机与PLC间采用SYSMAC WAY协议进行通信；该系统配置灵活，控制可靠．编程简单且成本低；通过现场实际应用，控制效果良好，达到了预期的控制目的。

Application of Multilayer Control System in EShan Fertilizer Plant

The dry ice production process automatic monitoring is based on the PLC distributed control system. The system is composed by a host computer and PLC, which carries on the global monitoring and control process. Host computer sets the PLCs parameters through monitoring picture , while receives the parameter, PLC execute the closed-loop control. Control system uses the Citect configuration soft- ware to design each kind of monitoring picture. The system uses SYSMAC WAY protocol to carry on the communication between computer and PLC, This system shows flexible configuration, reliable monitoring , programming simple and also the low cost. The control system has good control effect and achieves the expected goal in real application.