In 1995, various companies decided to create a working group to define an interoperability standard. These companies were the following:
- Fisher Rosemount
- Intellution
- Intuitive Technology
- Opto22
- Rockwell
- Siemens AG
Members of Microsoft were also invited to provide the support necessary. The goal of the working group was to define a standard for accessing information in the Windows environment, based on the current technology at that time.
The technology that was developed was called OLE for Process Control (OPC). In August of 1996, the first version of OPC was defined. The following diagram shows the different layers of OPC Classic with the underlying critical communication protocols—COM, DCOM, and Remote Procedure Call (RPC ...
