OPC: Plug and Play, not Plug and Pray
Naeem Ismat (Guest Contributor)
OPC is a proven technology NOW but AutomationMedia.com has been another voice in OPC technology from the very start, just due to the value which interoperability can bring to industry. In an effort to continue to play our part, in coming editorials we will take a simple but deeper look at OPC specifications like DA (Data Access), HDA (Historical Data Access), AE (Alarms & Events), Security, and XML DA and DX commands, which are widely used today. This may not cover all aspects but it will address most of those questions which I hear from industry. This is an effort to present things in a simple way. I shall try to clarify the information with graphics and examples.
According to Thomas Burke, President of OPC Foundation, "We believe the best educated end-users are really in the best interest of both OPC and the end-user community. We truly want to help the end-user to maximize their use of the technology by learning enough things about how to better use the products and services that are based on the OPC technology."
OPC Foundation (a non-profit organization), originally started in 1994 as a task force comprised of five leading industrial automation vendors--Intellution, Rockwell Software, Fisher Rosemount, opto 22 and Intuitive--to solve the driver problem. OPC Foundation is growing at a good pace, having four members in 1995 and 400 in 2006. The task force released the OPC standard in August 1996. Now OPC Foundation has become the international industry standard organization.
Some facts about OPC foundation:
The vision of OPC is to be the Foundation for secure reliable interoperability
Before we discuss Microsoft's offering for the Manufacturing Industry I would like to review with you a typical IT infrastructure of a manufacturing company.
In the 1970s, the central theme of information systems was hardware, and the result was almost always a hierarchical system centered on the company mainframe for commercial systems and perhaps manufacturing planning, with separate design, engineering and shop floor solutions.
By the 1980s, information systems for manufacturing had become more focused on applications, with numerous applications economically available for tasks ranging from process control and manufacturing planning to product design. PC networks and UNIX-based systems appeared in large numbers. "Open Systems" promised easy integration and access to data as well as vendor independence. If a new application needed a new operating system, then, so long as enough "Open Systems" standards were supported, the new operating system could fit into the enterprise?s Information Technology (IT) architecture.
The result of this was a variety of different systems on different hardware platforms which were difficult to interface and sometimes impossible to integrate. Each operating system needs its own specialist. Even dialects of UNIX each need their own specialist. Another common factor is that these systems are not only complex and expensive to support, they are also very difficult to change. Meeting the requirements (in terms of IT infrastructure) for BPR projects has become a nightmare for many IT departments, adding additional cost and complexity.
In my next ramblings, I will explain some very Common Misunderstanding/Myths about OPC.