Interoperability: OPC for embedded applications
Dayton, OH – OPC interoperability has brought connectivity to many things; next efforts may include embedded controllers, human-machine interfaces (HMIs), and programmable logic controllers (PLCs), Thomas J. Burke,
president and executive director, told Control Engineering during a
Burke, who joined the Part 5 committee in the home stretch toward a final draft, has some experience with collaboration. He’s thinking the next step for OPC United Architecture (UA) Platform is for HMIs, PLCs, Web services, and perhaps industrial networks.
“ We weren’t thinking about embedded applications when we started OPC UA, and we had to make a few subtle changes to accommodate. That includes removing or limiting security to create less overhead and allowing for client-server arrangements”, he says.
Burke ponders a future with a whole lot more interoperability, where Profibus and Fieldbus Foundation architectures could merge, field device translation (FDT) and electronic device description language (EDDL) unify, and different manufacturers’ PLCs interchange programming without translation. Many hoped IEC 61131-3 would lead to interchangeable PLC programs, but that never quite made it.
Filling in the divisions among many of these areas, Burke hopes, will be companion specifications to OPC UA. They would create a full XML schema describing data, metadata, and information. Mapping can happen to physical devices with help from domain experts. Many vendors have expressed interest in helping, Burke says, including Bechoff Automation, B&R, Emerson, GE Fanuc, Invensys (via Wonderware), Rockwell Automation, and Siemens. Organizations and groups interested include ISA88, ISA95, MIMOSA, PackML, and PLCopen. With hopeful tone, Burke says, “It’s all gelling. And it’s not just OPC anymore. We don’t need to compete, just work together to get standards adopted.” That idea’s going to be particularly useful as distributed control systems, programmable automation systems, PLCs, embedded controllers, PCs and enterprise systems continue expansion into each others’ worlds, he suggested.
“ We hear a lot of end users screaming because of lack of interoperability. It’s not about membership in organizations. It’s about stuff that works together.” Certification and many other efforts underway are expected to help, Burke suggests. Stay tuned. First cut at some templates may come as early as June.
– Mark T. Hoske , editor in chief
Control Engineering News Desk
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