At the end of my last entry I was discussing how OLE had advanced to a point where anyone could write a driver for an industrial device and make its data available to any OLE-enabled application. That was great – a huge step up from the days when almost no factory floor device could be connected to Windows. The problem was with everyone creating drivers there were no standards. An application using a scale driver from Bob and a barcode driver from Emily might be light years apart.
Clearly something had to be done.
After a few false starts and some delays the OPC (OLE for Process Control) Task Force released the first draft of a standard in 1995. A second release was crafted in 1996. By the end of 1996 the delivery of standard application drivers began in earnest.
And that clearly changed the use of Windows on the factory floor.
The OPC Task force continued to make improvements to the technology including the development of a Compliance Testing and Certification program. Improvements in Data Access, Automation, Data Logging, Batch Interface, Events and Alarms also have come about from this task force.
Today there are now whole companies that specialize in nothing more than delivering OPC Servers for hundreds if not thousands of Industrial Automation devices. Users all over the world use these servers to move data into SCADA programs, computational assistants and highly specialized control programs built on Windows Platforms.
So what was the OPC that the OPC Foundation task force defined? How did it work? Where is today? We’ll get into all of that next.