Based on Microsoftâ€™s OLE (now ActiveX),COM (component object model) and DCOM (distributed component object model) technologies, OPC consists of a standard set of interfaces, properties, and methods for use in process-control and manufacturing-automation applications.The
ActiveX/COM technologies define how individual software components can interact and share data. Backed by Microsoftâ€™s NT technology, OPC provides a common interface for communicating with diverse process-control devices, regardless of the controlling software or devices in the process. The goal of the standard is Plug-and-Play, a concept developed by Microsoft and a number of other companies a few years ago. By using a standard way of configuring computer hardware (and software interfaces) automatically, a device will easily connect to another and immediately work without the need for lengthy installation procedures or complex configuration. Instead of having to learn how to use 100 or more custom toolkits, users will only have to learn one set of tools, because all OPC drivers will work the same way. OPCâ€™s purpose is to compel the automation industry suppliers to push all device drivers toward a standard form. Essentially, OPC defines a common interface that permits interface development work to be performed once and then easily reused.
The OPC standard requires hardware suppliers to provide front-line data collection and distribution. They are the most familiar with how to access the deviceâ€™s internal data efficiently.These devices then
become OPC servers, providing data to OPC client applications consistently.Application developers can then write code in any language deemed appropriate.