Managing Automation - October 2007 - (Page 32)

[ COVER STORY ] Corp., and Dust Networks, Inc., are adding features to their wireless networking products that enhance reliability and data quality. To date, however, these features — like all wireless automation products themselves — are proprietary. Though industry standards that define how wireless products should guarantee reliability and data quality, among other things, are in the works, products that support those standards aren’t expected to be on the market for at least a year, vendors say. INTO OUTER SPACE Why are manufacturers worried about the reliability of wireless networks and the quality of the data they carr y? The most obvious concern is related to the fact that, with wireless, data is broadcast rather than contained on a wire. While that introduces security issues, it also raises reliability concerns. “With wireless, there is a distinct possibility that, rather than getting delivered, a message goes into outer space somewhere,” says Richard Caro, president of CMC Associates. But there are other, more specific concerns. Potential inter ference from other devices is one. Many wireless automation products toFACTORS INFLUENCING USE day, as well as the key OF WIRELESS wireless automation Manufacturers are looking for certain assurances before they will put wireless networks on the plant floor. standards now in development, are based on Wireless the IEEE 802.15.4 Reliability of security 23% data 28% technology, which typically uses radios operating in the 2.4-GHz band. However, other common Other 4% devices, such as other wireless networks, cordless phones, and even microwave ovens, also Single industry Need for single standard 18% use that band. network for many applications: 13% “We have found that Sensor battery life 14% the reliability of 802.15.4 Source: CMC Associates, ISA suffers in the presence of other wireless networks and devices,” says Dan Sexton, a project leader at GE Global Research, which, since 2004, has been evaluating wireless automation technologies under a contract from the U.S. Department of Energy. “Cordless phones, bad wiring, microwave ovens can jam the spectrum. That’s a big problem.” Some manufacturers also worry about interference from the wireless network itself. According to the ISA/CMC survey, manufacturers say they initially expect to deploy, on check list average, four sensors and other devices per 10 square meters using wireless technology. Eventually, they say, device density could be expected to rise to 10 to 15 devices per 10 square meters. Manufacturers worry that, as wireless device density increases, devices may begin to interfere with one another, CMC’s Caro says. And some manufacturers also worry about threats from terrorism and other conscious attempts to interrupt plant operations by targeting wireless networks. “It’s a very valid concern,” Caro says. “We don’t have any data that says a jamming device couldn’t bring down the whole network.” With all those potential problems, it’s no wonder that many manufacturers are holding off on widespread wireless deployments, at least until they can get more experience with the technology. “Data integrity and reliability in wireless environments is a huge issue for us,” says Ronald T. Morris, a senior engineering associate at DuPont Chemical Solutions, which, so far, has put in place isolated wireless networks, mostly for device and environmental monitoring. “It’s something that is going to take time and experience to deal with.” Wireless technology vendors are attempting to streamline that process by building features into their products that reinforce the reliability of wireless networking and help users track and validate data quality. Several vendors, including Dust, Emerson, and Invensys, have built their wireless automation products around the same type of mesh networking topology that is part of the 802.15.4 IEEE technology. Rather than routing all communications through a single gateway, mesh networks enable messages to reach a node or device via multiple paths. While that approach can carry a performance hit, it also means improved reliability and data integrity because, if one channel goes down or experiences interference, the network can recover on its own. And vendors are augmenting mesh wireless network reliability. Dust, which developed the time-synchronized mesh protocol used by many wireless automation vendors, has added to its products tools that let users continuously view the topology and performance of all elements of the wireless network in real time. On top of that, says Dust Marketing Vice President Steve Toteda, some resellers of Dust’s products — including General Electric, which sells a version of Dust’s wireless technology to pharmaceutical companies — have added a feature that automatically adds a software wrapper to each message moving through the network to let a network administrator confirm ma October 32 2007

Table of Contents Feed for the Digital Edition of Managing Automation - October 2007

Contents Take 1 Mailbox New Selling and Fulfillment Product Leads Plan to Transform Sterling Commerce Comtrol Closes Bizarre Chapter Involving Founder New Omron COO Outlines Four-Part Growth Agenda New Mfg. ‘Czar’ Will Have a Full Plate of Issues Lawson Embraces The Trend of Fewer Upgrades Notes Wanted: A Unified Infrastructure Needed: Greater Reliability Special Report: Innovation: Why Are So Many Coming Up Short? Transforamation: Beating the Odds in Global Supply Industries: Metals: Tracking Carbon Footprints Product Scan Advertiser Index Next

Managing Automation - October 2007

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