By John Rezabek, Contributing Editor
Back in the days of vinyl LPs and cassette tapes, we'd hear that millions of fans in Europe were going nuts for Slim Whitman and David Hasselhoff. No one could believe it. Could that many people across the Atlantic be hearing something we were missing? I think most of us thought it was a joke. Our peers outside North America evidently like something else better these days—intelligent field devices digitally integrated using bus technologies. I was a little dismayed when I heard ARC's Larry O'Brien report on current controls upgrade projects: 80% of end users surveyed were upgrading their control systems only, leaving field devices "as is." With all the press and supplier push to promote smart instrumentation, only one in five appear motivated to justify upgrading field devices when funding a revamp of antiquated or obsolete process control systems. But new technology is being embraced in the rest of the world.
What we have left is a large population of 50-somethings, whose ranks have been slashed by successive downsizing and reengineering, until the work far exceeds the man-hours to complete it. Whatever wise consultant-of-the-month decided we could do more with less was perhaps correct in the short term—the products still flow. However, the weary survivors can't be blamed for choosing to remain on the path of least resistance. We may tolerate muddling through learning a new technology on our home PCs or smart phones, but this sort of learning is unacceptable when the plant is down in the middle of the night, and waiting on you to get going again. Too many folks still fear that's what's in store for them with fieldbus.
Curiously, one reason to replace old systems is their inability to natively interact with smart devices speaking open protocols such as HART, Foundation fieldbus or Profibus PA. Why not incorporate upgraded field devices and infrastructure when seeking funds for host upgrades? Even a change-out of 10%, phased in over a year or more, creates a significant opportunity to learn the technology and exploit the capabilities of present-generation field devices. If there's a large installed base of digitally integrated field devices that use proprietary protocol field devices and host I/O cards, their days are numbered. One has a certainty of device-by-device attrition of obsolete technology, so why not plan to install an infrastructure to support the advanced protocols of this century?
The Fieldbus Foundation recently releasedInteroperability Test Kit Release 6 (ITK6), which makes field diagnostics and alert prioritization per NAMUR NE 107 mandatory. Phase C of the host registration or host interoperability support test (HIST) makes DCS support for many of these features mandatory as well. Engineers specifying systems to carry their plants into the future have an opportunity to exploit the features end users have worked to get included in the fieldbus standards.
As of this writing, two devices have already passed ITK6—a local indicator from Yokogawa and a thermal mass flow transmitter from Fluid Components International (FCI). While Phase C compliance has yet to be mandated, Phase B does test host support for field diagnostics, reports and multi-bit alarms as an optional feature, so users can specify it. Even if the features aren't available until factory acceptance testing, having them called out in the purchase order as a condition for progress payments will help ensure you get the capabilities you desire.
Complying with externally developed specs is expensive and time-consuming for suppliers, and fieldbus is no exception. I've heard a few complaints that uptake by users has been slower than expected, and jobs that "should have gone fieldbus" have not. However, this is not the case outside North America. Fieldbus Foundation's pie charts show growth in Europe, Africa, the Middle East and Asia is strong. ITK6 is making changes that will even make it even easier for those weary survivors peering through bifocals. We shouldn't shy away from the chance to make the most of it here at home.