Design And Implementation Of The Control And Monitoring Subsystems In Small Scale Water Treatment Engineering

The explosive development of modern computer’s hardware technology has beenstrongly boosting the innovation of configuration monitoring technology. Currently, suchtechnology is not only used in combination of large scale equipments, some small andmedium sized enterprises are also using a large mount of it, in an effort to low theirindustrial costs. This article chooses one part of small sewage treatment project asresearching target to analyze the specific development process, products as developmentplatform and using a configuration by taking S7-200series monitoring software—WinCC(WindowsControl Center).In the aspect of engineering hardware, a configuration monitor system’s hardwarecontains SIEMENS S7-200series’ combination of CPU-226CN PLC and EM223/EM222expanding module as its scenic industrial control system, CP243-1communication moduleas its communication access, which combine to a upper moniter PC827B through Ethernet.In the aspect of software, SIEMENS STEP7-Micro/WIN V4.0SP6programme software’sEthernet is used for its communication function. The programme process has aconfiguration monitor system with a man-machine operation interface, which is achievedby combination between OPC’s PC Access and WinCC6.2.The basic compostion of both software and hardware of the control subsystemand monitoring subsystem, the interface configuration of communication links, connection modes of different components and application environment are describedin this article. First, the development process of control subsystem includes Sequential Funtion Chart, UML (Unified Modeling Language) and application of LadderDiagram. Modularization programming idea is used to split the complicated large-scale system, which is then simplified into several relatively independent small modules. One of the small modules is developed as basis on which the main program is compiled step by step, to simplify the programming process and enhance theefficiency. Second, the designing method of monitoring subsysem is described, which is consist of three parts: modular structure, configuration of confugurable monitoring system and the application of configurable C Language script. The function of each module and the method of the man-machine interactive configuration interface are described, and a few sample program of C Language script are listed.Contrast to the old ideas, old technology, old products, the configuration monitoring system to reduce water treatment equipment and routine maintenance, saving troubleshooting time, improve equipment utilization and reduce operating costs advantages. In addition, the design there are still many inadequacies, such as: theHMI interface is relatively stiff, the monitoring function of the use of unskilled, long development time, the phenomenon of.