send back every data point, when there is growing capability at the instrument to do data logging, perform if/then decisions or otherwise exploit a smart sensor? In this scenario, the sensor-plus-radio is less a signal conditioner and more a smart device.”

“The more information, the more potential value to the users of the network,” Brooks says. “When you have what amounts to an aggregation of sensor inputs at the I/O (input/output) module itself, you can move enough information [to feed a variety of functional needs]. The broader the departmental participation, the better the business case for wireless.” Of course, the more functionality you extract from ever-smarter sensors and instruments, the more you move toward a high-end wireless application.

At the far end of the application spectrum, the perspective is no longer strictly automation-focused. The view broadens to include enterprise-wide viewpoints.  It is a world that is rapidly moving to a scenario in which every sensor or instrument dovetails into high-level, networked system architectures.

It is an approach favored by big producers, who can appreciate the benefits of highly integrated control strategies in general: comprehensive monitoring of equipment efficiency, close tracking of processes, top-to-bottom management of production resources. It is a world in which everything talks with everything else, with preference given to easily installed devices that interconnect quickly.

Big systems have many components, and the management of quantities of distributed components benefits from consistent deployment of preferred equipment from preferred vendors in consistent ways. It helps if the equipment conforms to open standards.

Meanwhile, the open standards themselves are in flux, with observers patiently (or impatiently) following the in-process development of ISA100, which encompasses an aggregation of standards including Ethernet and WirelessHart—and many others opting for less ambitious, but published standards. The latter include WirelessHart, IEEE 802.11x WiFi, ZigBee, a smattering of other radio standards, and even a range of cell phone technologies.

Jeff Becker, director of global wireless for Phoenix-based automation supplier Honeywell Process Solutions, delineates some of these standards, “Ethernet is gaining dominance in processing and manufacturing, so expect wireless Ethernet to follow. Process instrumentation favors WirelessHart and ISA100. For global operations, you find satellite and WiMax and others exploiting Internet Protocol. If you architect for unified communications at the center of all this, you are in a position to gain a number of benefits, from quick response to machine downtime, to tight inventory management, to responsive supply line and distribution management.”

Becker is a champion of the proposed IEEE 802.11n wireless networking standard, which ups the data rate by a magnitude—from 54 megabits per second over today’s WiFi to 600 Mb/s on 802.11n. Ancillary technologies are included in the draft standard, including multiple input, multiple output (MIMO) transmission technology, using multiple antennas to resolve higher rates of data than possible with a single antenna, and highly specialized multiplexing—simultaneous transmission of multiple data chains.

Over and above the technology, when planning integrated systems, Becker says, “You want, above all, to think of more than just the immediate application. Stay alive to where wireless can be used, where it might be used. This allows you to evaluate options with growth in mind. The more you search out flexibility and upgradeability, the happier you will be in two years.”

Security and reliability are key as well. “It’s not possible to talk enough about security,” says Rockwell’s Brooks.  “You can lock a switch or a control cabinet. You need to be able to lock radio transmissions as well, and that’s not just against bad people outside, but well-meaning personnel inside as well.”

Finally, continuously evaluate your resources, whether internal, consultant or supplier. A common theme is experience. Becker: “Now that wireless is hot, everyone is jumping in. Make sure your supplier has experience.”  Elpro’s Williams expresses the same sentiment: “Wireless is on the way up, and a rising tide floats all boats. Make sure you know who you are connecting with, and make sure they have wireless deployment experience.”

People are the final consideration—and this applies whether the application is one radio to one sensor or thousands of wireless devices in a comprehensive, interoperable network. As Paul Brooks says, “We spend a lot of time talking about wireless technology, but at the end of the day, it has to be installed and maintained by people. The reality is that people in plants want to be production experts, not wireless network experts. The easier it is at the human level to integrate your systems, the better.”