Wireless poses its own tangles

With so many wireless devices now available, the question is: can they all work together?

By Mike Spear

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As if presenters don’t have enough to dread — whether the laptop will boot up and the updated PowerPoint file actually is on it — add a new worry: is there a WiFi hotspot nearby? It was less than a minute, but it must have seemed an eternity to the product manager waiting for his laptop to connect to the Internet before he could start telling us, ironically enough, about his company’s latest wireless-enabled device.

The product was not targeted at the chemical industry in particular — it was a small machine-monitoring device with a built-in PLC (programmable logic controller) that could be programmed remotely — but it reflected the growing interest in wireless technologies now coming out of all the major control and instrumentation vendors. Anyone who has visited a trade show recently could be forgiven for coming away thinking “it won’t be long before we see wireless in our plant,” forgetting of course that it’s already there, if only in the form of cell phones and radios.

Persuading engineers, however, of the suitability of wireless technology for plantwide monitoring — let alone control — will not be an easy task, but it’s one being tackled with some enthusiasm by Hesh Kagan, director of technology for new business development at Invensys Process Systems, Foxboro, Mass., and also president of WINA, the Wireless Industrial Networking Alliance. “The good news in the emerging world of wireless technology,” he says, “is that more and more ingenious wireless devices are being introduced all the time. The bad news is that most of these utilize different, vendor-specific wireless protocols, technologies and access points to communicate with the wired communications infrastructure.”

As with earlier problems over different fieldbus protocols, that makes it difficult to get the most out of the data emanating from those devices and, says Kagan, “virtually impossible to ensure appropriate levels of security.” And just like initially with fieldbus, the wireless world is in danger of becoming bogged down in a plethora of protocols — WiFi, WiMax, IEEE 802.15.4, RFID, ZigBee, VoIP, not to mention an abundance of proprietary protocols, all of which are being put to use in the ever widening range of wireless devices coming on to the market.

Invensys has recently joined forces with Apprion, Mountain View, Calif. — whose chief technology officer, Peter Fuhr, is also a member of the ISA SP100 committee on wireless communications — to develop a different approach to implementing wireless on a plantwide basis. This is said to provide a common access point for all open and proprietary wireless systems, and offers built-in security. At the heart of the approach is a family of access points, one for each protocol, similar to communications multiplexers. “You can rack-and-stack the different protocols,” Kagan says. “We take access points — a necessary evil from a vendor’s perspective — and their security issues off the vendors’ hands, and we know how to integrate them into the IT infrastructure.”

Although the initial focus for this “Secure Wireless Architecture” approach is primarily on condition-monitoring applications, Kagan thinks it won’t be long before process measurement applications are included. The product is already undergoing beta tests at a number of chemical sites in the U.S., where it has demonstrated savings of over $1 million on a $250,000 investment in infrastructure. With wiring in some plants working out at more than $1,000 per foot, he expects cheaper, more flexible wireless technologies to grow in popularity, especially at large sites — but, significantly, not to replace wired communications completely.

Meanwhile, getting back to our slightly worried presenter, he got there in the end, but not before some wit in the audience reminded him of the venue — slap bang in the middle of London’s Fleet Street, formerly home to the nation’s newspaper industry. Now there’s a centuries-old communications medium that’s stood the test of time.

Mike Spear, editor at large
MSpear@Putman.net

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