Asp.net Ajax-based Data Acquisition, Monitoring System Design And Research

SCADA (Supervisory Control and Data Acquisition) system, the most important subsystem of Enterprise Management Information System, is widely used in processing control system and automatic maintenance scheduling system.It can help the enterprise management to decide and diagnose problems.Most SCADA systems nowadays are established on CORBA/Java or DCOM/ActiveX architecture, and they have come into a mature stage. CORBA/Java uses Java Applet to realize process supervisory control and Java Applet has a restriction on safety class of different browses. COM/ActiveX architecture supports asynchronous communication indirectly, and CORBA/Java posseses a very good openness.This dissertation is written under the background of some waterworks schedule System development, and design a SCADA System based on ASP.NET AJAX and OPC which have absorbed the advantage of CORBA/Java using client agent and DCOM/ActiveX using OPC to acquisite data.System finally realizes communication compatiblity as well as real time sharing among workshops inner enterprise.The first chapter of the paper introduces the research background and the paper structure.The second chapter elaborates the SCADA constitution and basic function, and sums up shortcomings of the two regular SCADA architectures. The third chapter designs a SCADA system based on ASP.NET AJAX and OPC,and introduces the related technologies.The forth chapter elaorates the design and implementation of the SCADA Server, which is the core section to the SCADA system.The fifth chapter compares three programming models and then brings out the solution using ASP.NET AJAX Client calls the Web Service asynchronously to achrive the SCADA Client expresses static flow diagram and dynamic real time data simultaneously.The sixth chapter design a trend subsystem based on DCOM/Activex.At the end of the paper summarizes the whole design and gives out the expectation.Enterprise management don't need field inspection any more by using Internet Explorer to view the SCADA system based above ASP.NET AJAX and OPC on the Intranet.The SCADA system is going to become an important tool to realize manufacturing automation.