Mmmm, Mmmm...COTS

For years, the distinctions between DCS, PLC, and PC platforms have been blurring, and "white box" hardware once considered too wimpy for demanding industrial applications has been finding its way into the plant. But until now, there have remained distinct camps: those adamantly in favor of single-purpose, proprietary industrial systems of one kind or another, and those who prefer PC-based open systems despite the insecurities that freedom might bring.

This year, those camps finally seem to have merged into one. Researching this article, we have seldom seen such complete convergence of opinion among users, systems integrators, and vendors. The entire control system community seems to agree that the time has come for controllers to be based on commercial off-the-shelf (COTS) hardware.

This unanimity of opinion is a great sign for the future of COTS because it indicates vendors are on the same page as users. This will help vendors to develop COTS control products that truly serve process industry needs.

Examples of this united front abound. "Rather than expend the costs of developing specialized hardware and proprietary operating systems, vendors [that use COTS] can devote more resources to developing control applications and solutions," says Glenn Richter, a project engineer with Milwaukee-based We Energies.

"COTS allows us to focus our resources on the value-added applications required by our targeted markets--the power generation and water/wastewater treatment industries," reports Steve Schilling, the vice president of product development for the power & water solutions division of Emerson Process Management www.emersonprocess.com).

All agree that COTS has a better price/performance ratio and much lower development costs than proprietary solutions. "Costs are lower and there is a much faster evolution of the hardware and software platforms," according to Richard McCormick, a process control engineer with Ultramer Ltd., Levis, Quebec.

"COTS offers faster implementation, faster enhancements, volume benefits in quality, more interfaces, and less custom engineering for hardware and software," observes Jeff Brown, a product marketer for Beckhoff Automation (www.beckhoffautomation.com). "This reduces our need to amortize those costs over longer life cycles or charge higher costs to customers."

Even with respect to reliability, the last redoubt of proprietary solutions, COTS is winning the war. "COTS systems are more reliable than purpose-built systems because COTS products are used in control solutions worldwide and have been for years," says Chris Ward, a senior design engineer with systems integrator ROV Network Ltd., Aberdeen, Scotland (www.rov.co.uk). "If they have a bug, someone will find it. Handcrafted systems cannot be proved reliable until they have been properly punished for a few years."

Vendors agree that COTS is up to meeting reliability requirements. "COTS technology continues to get better and better in terms of cost-to-performance and, in many instances, now matches purpose-built components in terms of reliability," reports Roland Gendreau, product marketing manager, Foxboro Automation Systems (www.invensys.com).

Another sign of acceptance is a recent press release from the Open Modular Architecture Controls (OMAC) users group (www.omac.org). According to the release, OMAC has been traditionally associated with open architecture controls for CNC applications. The users group reports that OMAC has now evolved to an epicenter of activities applicable to process and hybrid manufacturers in addition to its original discrete manufacturing constituency.

End users and systems integrators usually have unique and interesting takes on vendor spiels, but not in the case of COTS controllers. To a striking degree, both parties agree COTS controllers are an unstoppable force that will eventually engulf the entire real-time process control market.

Given this agreement, it was perhaps inevitable that the last line of proprietary control is falling to COTS. The mighty DCS, long the mainstay of large process control applications and certainly the most formidable bastion of proprietary hardware and software, is rapidly crumbling in the face of the COTS onslaught.

What Happened to My DCS?

All of the major DCS vendors have switched to COTS to some extent, some to a striking degree. Westinghouse (now a part of Emerson) has deployed its WDPF system for decades in traditional large-scale DCS applications such as power plants and water/wastewater plants. The company's newest-generation DCS relies totally on COTS for control.

"Our Ovation controller uses a Pentium processor single-board computer on a standard PCI backplane with the VxWorks real-time operating system," says Schilling. "The standard benefits of COTS gear apply: lower cost, faster time to market, and interoperability."

Ovation customers agree. "There is certainly an advantage to manufacturing in COTS quantities as far as spreading out development costs," adds Richter of We Energies. "This has had a tremendous impact on control systems where, for example, we used to deploy proprietary operator consoles sparingly. Now workstations are inexpensive to the point they can be added at will."

Foxboro was one of the first vendors to jump on the COTS bandwagon. Its I/A series employs COTS components such as Microsoft Windows-based workstations and servers from Dell, standard Intel and AMD microprocessors, VRTX real-time operating systems, and Ethernet. Gendreau says, "Not only do COTS components cost less, the automation vendor can often source them from multiple vendors with rapid lead times to support modern just-in-time manufacturing practices."