SCADA / Fieldbus

Secure your wireless information channel

Among the obstacles that process control pioneer Dick Caro sees affecting the advance of wireless technology are the security of the information channel and powering wireless devices.

By Terry K. McMahon, CONTROL Columnist

AS ANNOUNCED by its 2005 president, Don Zee, ISA’s new tag-line, “Setting the Standard in Automation,” plays well with a major theme of the recent ISA Expo 2005—industrial wireless data communications for measurement and control. Wireless was everywhere at the Chicago event, in technical symposia, tutorials, special events, and throughout the exhibits. ISA also announced publication (also in portable, electronic document format) of a major text on industrial wireless, and cited continuing progress by its SP100 Committee, led by Wayne Manges (DoE ORNL), in formulating an effective standard for industrial wireless to further accelerate development of this technology.

Dick Caro’s new book, Wireless Networks for Industrial Automation, 2nd Edition, is an authoritative compilation of wireless network fundamentals, existing standards and special requirements for industrial automation. Caro addresses the application of various wireless protocols including WiFi, Bluetooth, ZigBee and 3G, commenting on their pluses and minuses.

Among the obstacles that Caro sees affecting the advance of wireless technology are: the security of the information channel and powering wireless devices. The latter is not a small problem. Current battery technology is less than satisfactory in many industrial applications. Low-power-consumption network technologies like ZigBee can help, but these have other limitations. Optical methods, such as photovoltaics, and pneumatics aren’t presently even in test mode. The book also discusses magnetic induction and broad beam microwave methods.

In his book, Caro states, “NASA has long been interested in transmitting electrical energy from solar collectors in stationary earth orbit to ground stations that would convert back to electrical energy. While the energy would be solar, the transmission would use a broadly spread spectrum of microwave radio…This method may actually become practical when the power required is only a few milliwatts, but currently there is no known development of microwave power broadcasting for terrestrial applications.”

About 50 years ago, the self-winding wristwatch was a great technical innovation.  Enough energy could be recovered from random arm movements of the wearer to keep the watch ticking, if not forever, then for a very long time. Perhaps the ubiquitous phenomenon of industrial vibration, which ruins fourier transform infrared (FTIR) applications, could be harnessed.

Caro, of CMC Associates in Acton, Mass., was a pioneer in the fledgling field of computerized process control in the 1960s. After receiving his M.S. in chemical engineering from LSU in 1964, he developed and installed computer-based control systems for Union Bag-Camp Paper Corp. at its mills in Savannah, Ga., and Franklin, Va. One of my early assignments at IBM in 1961 was at the Savannah mill, where we ultimately installed an IBM 1710 on a tall oil distillation tower to insure purity in the fatty-acid fraction.

The pulp and paper industry was ready for digital computer control in the 1960s because feedback methods, which were widely employed in the chemical and petroleum industries, were not generally applicable because key measurements were not available and process response times were typically long. Consequently, there was a lot of low-hanging fruit to be harvested through improved control.

After stints with Foxboro, Modcomp and Autect Data Systems, Caro joined Arthur D. Little (ADL) where his principal focus was new product innovation and telecommunications. He was awarded two U.S. patents in the mid 1990s for Commercial Advance, a method for skipping commercials while recording TV broadcasts. This technology has been licensed to most VCR manufacturers.

While at ADL, Caro served on ISA’s SP50 fieldbus standards committee. When the leadership of this important group became vacant, he was asked to re-energize and complete the effort. The ISA 50.02/IEC61158 document is now the technical basis for Foundation Fieldbus, Profibus PA and other commercial implementations of this technology.

Now in private practice, Caro has been recognized by ISA and other organizations. (CONTROL magazine inducted Caro into its Process Control Hall of Fame a few years ago) for his singular achievements. He is currently serving on ISA’s SP100 wireless standards committee. My admonition to ISA’s leadership: This guy’s a keeper. Don’t let him get away.

  About the Author
Terrence K. McMahon of McMahon Technology Associates, Leonia, NJ is the "Around the Loop" columnist for CONTROL magazine and He can be reached at

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