Hank Hogan for Control Engineering
With process safety and sensors, sometimes garbage in equals more than garbage out. Because these devices measure pressure, temperature, flow, level, and other process parameters, they play a pivotal role in determining a process unit’s output. A wrong reading can produce waste or create a catastrophe that costs lives and makes national news.
The old saying about kitchens and heat applies, with a twist, to the process industries and rugged human machine interfaces (HMIs). Increasingly, these intermediaries between people and equipment can take the heat—not to mention the humidity and the vibration. They can do so thanks to advances in HMI design, manufacturing and technology.
No man is an island, but then neither is control equipment in today’s world. Devices that at one time might have operated on their own are now networked together, a change that’s enabled more nimble control and increased the flow of information in both directions. Those are the benefits, but gaining them does require the network to work.
When done correctly, safety systems can be fun — or at least can make sure what's amusing doesn't turn tragic. A look at two case histories shows how integrating safety and control systems can cut costs while improving safety and reliability. The two examples are literally and figuratively from opposite ends of the earth.
When winter strikes, you need heat to beat back the cold, and it’s best when the fuel is reliable, plentiful, and relatively clean burning. This year, consumers in the U.K. have a new source for that heat, natural gas and condensate pumped across the ocean from Norway’s undersea Ormen Lange gas field.
When questioned, Magnus Hermansson, general manager for GE Healthcare’s Life Sciences in Uppsala, Sweden, notes his facility doesn’t fall under direct FDA (U.S. Food and Drug Administration), scrutiny. What the plant produces, after all, is the chromatography media used in protein separation and purification.
Eelco van der Wal, managing director of the Gorinchem, Netherlands-based industrial control organization PLCopen, is on a crusade—one that impacts applications and, hence, the part of software reliability control engineers are responsible for. His efforts, though, will only provide part of the solution.
Matt Chang is a hardware design engineer at Opto 22, the Temecula, CA-based automation hardware and software manufacturer. As such he has a hand in the development of new products, and something about embedded control chips used to bother him. The chips would have features that he, or any automation hardware designer, would never use.
Keith Jones isn't the type who'd use a hammer to turn a screw. He believes in using the right tool for the job. For Jones, president of automation systems integrator Prism Systems Inc. of Mobile, AL, that means that the right network for some parts of particular automation and control installations isn't one with more bandwidth and greater capabilities, like Profibus or ControlNet.
It's hard to imagine anyone using the old drafting table and instruments to design anything today, but Tegron LLC used to employ labor-intensive techniques to create and revise drawings to automate customers' industrial processes. Under the old approach, recalls Tegron design leader Wayne Gatlin, each drawing required multiple checks by various people.