ISA Expo 2006: New wireless capability will bring smart sensors to legacy environments

-- Control Engineering, 11/16/2006

Smart sensors can give more information about your process, but only if you can hear what they have to say. In an environment where instrumentation is hard wired with only analog process variable information, there is no mechanism to communicate diagnostics. But soon, wireless networks will provide a method that crosses vendor platforms. HART Communications Foundation's impressive display at ISA last month in Houston brought together a dozen companies to endorse a coming standard for wireless solutions to support smart instrumentation in new and legacy environments.

"Of the 20 million-plus HART-enabled devices currently installed around the globe, only 10% are delivering their full diagnostic potential, a state of affairs that is poised for change," says Ron Helson, HCF executive director. "Development of the Wireless HART standard along with the new enhanced DDL (device description language) capabilities opens the door to the untapped functions in HART devices and simplifies the task of integrating instrumentation from multiple vendors into plant asset optimization systems."

If you have some of those 90% of HART devices that only deliver a process variable, and want to use the diagnostic capabilities but can't afford rewiring or changing to a fieldbus platform, wireless communication may indeed be the answer. HART demonstrated how the process variable can continue to come to the DCS via existing wiring, while digital diagnostic information can be transmitted using a wireless adapter in parallel. A wireless gateway provides the path for these data to reach your device management application. In new applications, the same wireless network can also carry the process variable, eliminating the need for cabling entirely.

HART stressed the universality of the coming standard, showing that wireless HART-enabled instrumentation from one vendor will be compatible with any other, at least as far as communication capability is concerned. Devices from any of the participating companies (Click here for a list) will talk to each other and gateways, eliminating the need for proprietary platforms, just as groups of manufacturers support the same fieldbuses in the wired world. The common denominator is the HART protocol. Given the rapid advances made in the last few years, wireless communication in industrial settings enjoys greater reliability, flexibility, and lower costs than ever before. Now there may be some welcome common elements that will drive functional compatibilities, too.

Control Engineering Daily News Desk
Peter Welander, process industries editor