OPC stands for Object Linking and Embedding for Process Control. It fills the gap between Windows applications and on-site process control applications.
Before OPC, each application developer had to write a dedicated interface function in order to access data information from field devices.
Due to the continuous upgrading of products and the wide variety of field devices, developers previously had plenty of work to do, so they needed a device driver with high efficiency, reliability and openness.
That’s why the OPC standard appeared, it’s based on Microsoft’s OLE technology, which allows multiple computers to exchange documents.
It is possible to create an open inter-operable control system software with DCOM technology and OPC, The task of developing the access interface is left to the hardware manufacturer or third-party manufacturer. When the OPC controls the user/server mode, the OPC server will solve the contradiction between the software and hardware manufacturers, completes the integration of the system, and improves the system.
OPC is a software interface standard between a data source (OPC server) and a user of data (OPC application). The data source can be a control device, such as a PLC, a DCS, or a bar-code reader. Depending on the composition of the control system, the OPC server as the data source can be either a local OPC server running on the same computer as the OPC application or a remote OPC server running on another computer. The OPC interface is an interface standard with high thickness flexibility for many systems.
OPC is very important because in industrial control systems, different vendors need to exchange data between devices. The data needs to be accessed from one manufacturer to another manufacturer, to be docked with their production control system. It is obviously impossible to develop a proprietary agreement, therefore, the OPC is adopted to solve this problem.