OPC stands for OLE for Process Control, which describes the standard interface for data exchange under Windows (OLE – Object Linking and Embedding) in a customization for process control. A community of over 300 global companies called the OPC Foundation, since 1996 has specified the scope and functionality of this standard. OPC consists of a whole range of specifications that restrict the exchange of messages, histories and data to a well-defined scope of interfaces. So-called OPC servers are the data providers whose services are used by the OPCC clients. The focus is on the servers: they create the connection between the OPC world and the technical systems. Manufacturer-specific technologies have thus largely become obsolete.

For the subsystem supplier, the main advantage is an intrinsically verifiable and demonstrably functional interface during the acceptance. Public documentations are limited to data point and message lists, version differences are relevant only within the own house. The commissioning is shortened considerably, because now the operation of the entire system can be checked by own tools prematurely. The manufacturer of the control system is limited to what the control technology is supposed to do: the preparation and management of data for the operator. Cost-intensive implementations of interfaces are largely eliminated. The biggest advantage is the operator. In addition to the time and cost savings for system integration, subsystems and control technology are interchangeable. No manufacturer is able to use proprietary technologies to deprive customers of functionalities or to make customer adjustments through an unjustified pricing policy. Since all data of the overall system are available transparently, the operator has the option of carrying out any further processing of the data independently or with the help of external service providers. The previous restriction and thus dependence on the temporary manufacturer of the sub- or control system is thus eliminated.

Our early decision to integrate the OPC interface has made life easier for us in more than 1,000 projects. Often it is more than 70% of the data points that we can integrate cost-effectively and reliably via OPC servers. In the meantime, we are even developing a large part of our new subsystem interfaces only as OPC servers and offer them to the respective manufacturers for redistribution.