文中提出了一種采用以操作員工作站為上位機，可編程控制器（PLC）為下位機，
利用ControlNet 網絡進行數據交換，對系統各設備參數值進行在線監控顯示的自動監控系統的方案。PLC 采用美國ROCKWELL 公司的ControlLogix 系列產品，實現數據采集、控制、故障檢測等功能；同時采用了雙PLC（CPU）運行模式，實現了控制系統的熱備功能；上位機工作于Windows 環境下，使用Citect 工業控制組態軟件開發人機界面，實現了實時動態顯示，數據的自動采集處理，故障報警，實時、歷史報表的打印等功能；ControlNet網絡連接上、下位機，通過OPC 技術充分保證信息傳遞的快速性。此外，本系統性能穩定,具有操作簡單、可維護性高、易于擴充等優點。
關鍵詞 監控系統，ControlNet，PLC ，OPC，Citect
Abstract：This text put forward a kind of design to constitute the Supervisory System that for the control mode of operator work station is regarded as the master computer and programmable logic controller (PLC) as the slave computer, ControlNet as the bus for data exchange. We adopts a kindof advanced PLC of ControlLogix series of ROCKWELL corp. in the United States, which realizes the remote data collection, the control functions and the malfunction examination of the devices etc. The master computer works in the Windows environment, configured by Citect . With the master computer, the monitor functions which we acquire from the supervisory system are as follows: displaying the entire technologic process dynamically, lively, and realistically, automatically saving data, correctly alarming in time when abnormal case happen and printing reports according to demand at any time. We connect master and slaver by ControlNet network, and OPC technic guaranteed the speediness of transmission of information. In addition, the system is with steady performance and easy to maintain, simple to operate and prone to extend.
Keywords supervisory system, ControlNet, PLC, OPC, Citect