The Design Of Monitoring Software Based On OPC

With the rapid development of science technology, monitoring software is playing an increasingly important role in the industrial production. At the same time,automation systems have more and more needs for large-scale information-sharing, thus the requirement for openness of the industrial control systems has become higher. The development of traditional industrial host computer is based on devices,the stability and complexity of programmes are limited to communication protocol of bottom hardware.And DCS, FCS and other systems which are widely used in industry are short of a unified interface standard, it is difficult to connect with multiple field devices. In order to meet this need, this paper propose a monitoring software design method based on OPC technology.OPC (OLE for Process Control) defines an industry standard interface based on the Microsoft's COM / DCOM technology, OPC technology applies Object Linking and Embedding technology in the field of industrial process control,it also provides a standard data access principle which makes whatever form the field device it is, the client will access in a unified way, thus ensuring the software is transparent to clients.In this paper, we use VC6.0 as a development tool to carry out the design and development on the OPC client software program based on in-depth study of COM technology and OPC Data Access specification. Explain the design ideas of each function module and make the client molule as emphasis. The designed OPC monitoring software can connect with multiple OPC server and can read and write datas from OPC Server,realizing the data transmission between monitoring software and multiple field control devices .The paper aimed to diesel monitoring software, designing the monitoring software based on OPC.It realized the operation of displaying field datas real-timely,alarming,watching history curve and report,realizing the diesel monitoring on site. The design idea of this paper has advantages of openness and simplicity. The monitoring software designed can be used in practical application, realize accessing datas of multiple devices in a unified approach ,and avoided the repeatability of the development of drive programmes.This way can not only save cost, but also protect the technology of hardware provider. The experiment proves this design is in accordance with the direction of the software development and thus has broad application prospects.