Many Ways to Cut the Cord

May 6, 2009
Wireless communications are still a small niche market in the industrial world, but interest levels are high, and development programs are many.

In often-changing automation facilities, being able to reconfigure lines and floor plans without worrying about cable runs is a huge benefit.

Many companies have already installed wireless networks, helping erase the reliability concerns that were once expected to bar wireless links from the factory. ARC Advisory Group Inc., Dedham, Mass., predicts that wireless products for process manufacturing will grow 32 percent per year, hitting $1.1 billion in 2012. Products are emerging rapidly, prompting many to tout wireless as a way to cut costs and headaches.

“One of the best ways to eliminate wiring costs and problems is not to use any [wiring],” says Carl Henning, deputy director of the Profibus Trade Organization, in Scottsdale, Ariz. “Wi-Fi and Bluetooth both come along with Profinet for free because it’s Ethernet.”

Industrial Bluetooth?

That Ethernet compatibility has made Wi-Fi (for Wireless Fidelity) a key player in the market. Wireless Hart, ZigBee and proprietary schemes are all challenging Wi-Fi. Bluetooth is also expected to extend beyond its huge cell phone base, gaining a role in industrial facilities. “It’s simpler than Ethernet. Ethernet is more costly in dollars, power consumption and its software footprint,” Henning says. The small amount of memory in phones makes it attractive for industrial equipment designers who want to keep storage requirements low. Henning expects to see a document for an industrial Bluetooth specification later this year. It will focus on the protocols needed to ensure reliable communications in harsh environments, he explains.

Another specification that was completed last year, WirelessHart, is expected to gain solid acceptance for the many devices that don’t require much bandwidth. At the sensor level, “the completion of WirelessHart is a major milestone,” Henning adds. That network complements Ethernet protocols, providing a way to integrate the networks without compatibility problems. Network proxies will be a critical aspect of this integration, he says.

The availability of more protocols will probably boost the usage of wireless. Alternatives often mean that users can select a technology that’s well-suited to their needs. Still, most suppliers feel that it’s prudent to move slowly. Wireless can serve as a useful tool for prototyping before a network is deployed widely.

“Using wireless in a pilot project can be an effective, low-cost way to provide proof of concept for a project before investing in costly, permanent wiring runs or making an enterprise-wide commitment to wireless,” says David Crump, marketing manager at vendor Opto 22, in Temecula, Calif.

When it’s time to move into production, plant managers need to make sure they’re getting products that fit with their other equipment. At this early stage of the game, some vendors offer wireless networking solutions that are customized. These wireless I/O modules or I/O racks are incompatible with their standard components. “The key is to specify and purchase a wireless solution that’s part of your vendor’s standard offerings,” Crump advises.

Related Feature - Ethernet’s Reach Grows In ManufacturingTo read the feature article relating to this story, go

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