BP Pipelines of North America, in Forest City, Ill., operates a network of pipelines in the United States that transports 450 million barrel-miles of petrochemicals each day. The company’s control center in Tulsa, Okla., is responsible for the transport of oil and natural gas from South-Central and Midwest oil fields to locations nationwide. Last year, management at the Tulsa control center decided to add leak detection to the supervisory control and data acquisition (SCADA) system to monitor pipeline leakage. The SCADA system gathers data from production systems and stores it in a Sybase database that has been modified for real-time applications.

The challenge was to feed process data from the Sybase database to the leak detection system. “We tried for months to find an OPC server that would communicate via ODBC (open database connectivity) to the real-time Sybase product,” says Chuck Amsler, team leader for SCADA applications at BP Pipelines. “It was an older version of ODBC, and we just couldn’t get at the data. None of the applications we tried could do it.”

Amsler turned to Cogent Real-Time Systems in Ontario, Canada, to see if there was a way that the company’s OPC DataHub product could be used to make the connection. He spent a few hours consulting with Cogent’s technical staff and came up with a DataHub script that can support a connection to the SCADA system and queries the Sybase database. Once the process data reached the OPC DataHub, it was just a matter of bridging the data to the leak detection system’s OPC server.

Now, the data flows from the SCADA system to the leak detection system reliably and consistently. “Once we saw how easy it was for the OPC DataHub to make the connection, we decided to use it to log the results,” says Amsler. “With Cogent’s help, we wrote another script to transfer the leak detection calculations back to an Oracle database for eventual reuse by the SCADA system.” On the Oracle side, the OPC script allows Amsler’s team to modify the logging process even while the system is running.

For 10 years, OPC has offered open connectivity from automation to enterprise systems. OPC originally stood for OLE for process control, based on a Microsoft Corp. technology called object linking and embeddng. Over the past decade, though the OLE name has faded away, OPC technology has gained importance as data sharing has become even more important. So has the need to connect devices and applications from a variety of vendors. Just like the printer driver that allows a wide range of applications to interface with a printer, OPC is the driver installed on computers to help software applications interface with industrial data sources.

These data sources can include control systems, programmable logic controllers (PLCs), databases, historians, scales, temperature gauges, maintenance systems and more. The recently developed OPC UA (Unified Architecture) takes OPC further into embedded devices and up to enterprise systems, while relying on Web Services rather than Microsoft common object model (COM) and distributed COM (DCOM), which are slipping into legacy status.

OPC comes of age

The sweet spot for OPC is its ability to make a wide range of devices and applications interoperable. “There’s a need for openness, so you’re not bound to one vendor, so data isn’t stuck inside one machine, so data isn’t stuck in the plant,” says Eric Kaczor, product manager for software, at vendor Siemens Energy and Automation Inc., in Alpharetta, Ga. “Customers want to design a system that is not bound to one vendor’s proposal.”

OPC has become the default driver for connecting disparate vendor devices and unlike applications. “The most important thing about OPC is that it’s the standard in the industry,” says Roy Kok, vice president of sales and marketing at Kepware Technologies Inc., a Portland, Maine, supplier of communication software for automation. “It has become the interface to every product on the market, and it allows you to choose best-in-class products.” He notes that there is a huge installed base in OPC. “It’s an extremely successful standard.”

The vendor community has recognized the importance of OPC and has responded by building OPC into its products. “As time goes on, vendors are making their products more solid on OPC. Companies are betting a lot of money on OPC’s ability, and it’s paying off,” says Randy Konder, president of the OPC Training Institute, in Edmonton, Alberta, Canada.

While OPC is not built to connect plant-critical systems, it is being widely used to share non-critical data. “OPC ...