Application of OPC in Automatic Control System

During this period of time, I have been working on Industrial Automatic Control Projects. PLC Used Siemens. At that time, the host computer used Siemens WinCC, which was a nondescribable C, it makes me really intolerable. Without event-driven, it cannot be called modern software. After several days of diving on the Siemens BBS and a waste of water with engineers in Beijing, I finally found the future direction of self-control software application, OPC. OPC is divided into two parts: OPC server and OPC client. OPC server is a component object based on DCOM and is responsible for connecting to PLC. Similar to an adapter, each PLC manufacturer has an OPC server for its own PLC, and it is also provided by a third party. The OPC client is actually an application implemented by itself based on the OPC protocol. Program . Currently, many third-party vendors provide OPC client components for. Net or Delphi. Application developers only need to use components to read data provided by OPC server. So OPC is similar to ADO, but only divided into client and server. Through ado, applications can connect various databases conveniently without the need to consider the specific implementation of the connection. Similarly, as long as the connection from the OPC server to the PLC is configured, the application writer does not need to consider which lib to call to connect to the PLC, and only needs to connect to the OPC server through the standard OPC client. There are many OPC client components vendors, which are introduced in OPC programmer's connection. I originally used the kassl dopc, but only trial, with a full set of source code 500 $, trial has nothing to do with it, but when the program starts, a prompt box will pop out to remind you to go to its website. As a result, one day I downloaded iocomp because I needed industrial interface components. unexpectedly, I found that iocomp also implemented the OPC client. It seems that even in the slightly conservative industrial control industry, the pace of new technologies and standardization is still unstoppable. The benefits of using OPC are as follows: 1. Because the PLC is connected through OPC, any development tool can be used for application development, such as Delphi, C #, and VB, it does not need to be limited to the poor development tools provided by PLC manufacturers, thus reducing the programmer's learning cost and the company's Employment Cost. 2. Since OPC is an adapter, if the PLC changes, you only need to replace one OPC server for the connection between the host computer and the PLC. It is no exaggeration to say that OPC represents the direction of the interconnection between the lower computer and the upper computer. With OPC, we can choose the upper development tool as per our preferences. The productivity improvement is obvious. SIEMENS automation: Drawing Foundation http://www.opcfoundation.org/OPC connection http://www.opcconnect.com/Kassl http://www.kassl.de/ioComp http://www.iocomp.com/