OPC (OLE (Object Linking and Embedding) for Process Control) is the successor of DDE technology.
According to the OPC Foundation, “OPC is open connectivity in industrial automation and the enterprise systems that support industry. Interoperability is assured through the creation and maintenance of open standards specifications. There are currently seven standards specifications completed or in development (“What is OPC?”; www.opcfoundation.org)”.
OPC is based on a series of approved standards and technologies of the consumer computer world. It was originally based on OLE COM (Component Object Model) and DCOM (Distributed Component Object Model), which provide the framework. Microsoft even added OPC standard to the OLE specification. OPC interface applications are built once and used several times, thus are approved and under constant quality control.
With OPC, data can be exchanged efficiently using a standardized interface, hence vendors do not have to implement their own communication drivers. Therefore it allows vendors to reduce implementation costs and save time, thus reducing the project cycle time.