equipment health monitoring interest, right now you find that restricted to large multinationals,” Becker says. “They tend to have the most sophisticated plant maintenance approaches, and they’ve taken the time to document the savings in good reliability and maintenance practices.”

There are some interesting wrinkles involving hybridizing or mixing-and-matching technologies in both devices and infrastructures. While it is not yet fully certified to be ISA100-compliant (the term used for it today is “ISA100-ready”), Honeywell Enraf’s new SmartRadar FlexLine device combines both IEE802.15.4 wireless communications with a radar tank level gauge. “It was a challenge to put both a radar radio and a communications radio in the same package,” Becker says. “But it adds high precision compared to conventional level gauging methods. That brings it in line with the growing need to be absolutely certain about hydrocarbon and chemical quantities while they’re in the process stream.”

For the network infrastructure itself, Becker cites a growing need for multi-protocol routing. “There’s a growing need for a centralized network that can control and isolate data from field instrumentation, traffic from mobile workers with wireless devices, and engineering traffic from mobile personal computers,” he explains. “The critical need is to sequester each type of communication. Engineering needs high-bandwidth access and firewalling to engineering servers for documentation and drawings. Sensor traffic has to connect with the DCS at a much lower bandwidth, but no less security. You need to make sure that data enters and exits the system at the proper layers and with the proper safeguards.”

We are likely to see more and more multi-function, multi-network backbones and devices as wireless sensors and instrumentation progresses. There might be more single-minded solutions if, first, existing industrial sites simply packed up their old stuff and bought all new; and, second, all the radio standards melted down into one single gold standard. But, neither one of those things is likely to happen. Even the new standards are resisting amalgamation. The proposed inclusion of WirelessHart in the ISA100 family of standards (ISA100.12) has withdrawn into disquieting silence, suggesting that the disparate underlying technologies are, well, disparate.

But the forces for diversity are extremely strong. Industrial equipment runs for decades. Newer and better models of anything used in production, with the exception of their electronics, remain significant capital expenses. While “capital expense” is a particularly bad word in a bad economy, it is never undertaken lightly, even in boom times. The result at most facilities is a mind-numbing assemblage of disparate generations of equipment and control tactics.

Then, too, no matter how much age they have on them, control structures, network protocols and device standards generally boast one or more specific strong points. Their installations tend to emphasize those strong points and work around the weak points. Understandably, engineers are slow to replace either the successes or the work-arounds when it means reining in a completely different set of strong and not-so-strong elements.

There is at least a partial answer. When everybody wants something different, configured in some different way, the answer is proliferation of options. Long before wireless was added to the mix, instrumentation/sensor purchase specification was already an exercise in configuration—sensor types and ranges, isolating diaphragm materials, mounting profiles, housing types, flange geometry…and this barely scratches the surface.

When it comes to the radio, the same modular approach applies. Here, because so many variables fall out of a given technology choice, you have to add a user interface and incredibly flexible, software-controlled electronics. Want WirelessHart? Plug the WirelessHart module into the main board. All the hooks into and out of the sensor voltages, all the data rates and bursts, all the protocol layers specified under WirelessHart come into play. Want ISA100? Plug in the ISA100 module. Want both? Well, maybe not.

The next few months will see continued introduction of a growing stream of new wireless sensor and instrumentation devices. It remains to be seen where the emphasis flows, since economic recovery will be a critical contributing factor. Will it be primarily maintenance-driven replacement across open ground, where trenched wiring is deteriorating? Primarily new installations in developing areas? New devices in response to new ideas? Whatever the final tally, 2010 should be one of the most exciting years in industrial wireless.

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