PAC—it’s one of those analyst-generated acronyms that seems to have
stuck, though it’s a term that continues to cause confusion in some
circles, as well as consternation in some vendor camps. It was late 2002 when Craig Resnick, a research director at ARC Advisory Group Inc., first published the term PAC—for programmable automation controller—in an “ARC Insights” document sent to clients. ARC, based in Dedham, Mass., coined the PAC term to describe a new class of open, multi-functional, integrated control systems that was emerging within the controls space occupied by that most venerable of automation workhorses—the programmable logic controller, or PLC.

“The PLC is very much alive and well, with a long life ahead,” Resnick assured readers in that “ARC Insights,” dated Nov. 20, 2002. But the document went on to observe that “the label ‘PLC’ simply understates the capability of current automation systems. As a new generation of functional capabilities pervades the market, the more apt notion of Programmable Automation Controllers (PAC) will displace its [PLC] predecessor,” Resnick predicted.

Growing fast
Today, more than five years later, PACs so far haven’t come close to “displacing” PLCs. According to a 2007 ARC study, the worldwide market for PLCs totaled $8.3 billion in 2006, and ARC projects compound annual growth rates at 7.3 percent for the category through 2011, when PLC sales will total nearly $12 billion.

PACs, meanwhile, are currently deployed in only about 5 percent of the applications that could potentially benefit from their use, Resnick estimates. But PAC sales are growing significantly faster than those of PLCs, he says. Though ARC hasn’t done a formal study on the topic, Resnick ventures that PAC sales growth lately has been running at 15 percent to 20 percent annually, and the total PAC market last year was probably “well north of a billion dollars. We have a long ways to go,” Resnick allows. “But I can tell you that sales [of PACs] continue to be very, very strong.”

The PAC terminology has so far been unevenly embraced by control systems vendors. Some have questioned the need for another industry acronym. But other suppliers were quick to begin using the name, as a way to help differentiate their products. And many contend that they were well ahead of the game in offering expanded, PAC-like controller capabilities before ARC came up with the name.

“What the PAC name did for us was to give us a way to identify what we were already doing, because people tended to lump [our product] in with PLCs, and in a number of ways, it’s dramatically different,” says Tom Edwards, senior technical advisor at Opto 22, a Temecula, Calif., vendor, speaking of his company’s Snap PAC family of controllers.
At Rockwell Automation Inc., the Milwaukee-based PLC and controls systems heavyweight, Ken Deken, vice president,
portfolio management, declares that his company’s ControlLogix platform, introduced in 1998, “from day-one has been a programmable automation controller.”

And at GE Fanuc Intelligent Platforms, the Charlottesville, Va.-based automation supplier, Controllers Business Manager Connie Chick recalls that when ARC’s Resnick first began talking about something called “PACs,” her company was already “in design phase” on a new controller line that met the PAC definition. The company recruited Resnick to help introduce the line—called the PACSystems RX7i—at road shows and Webinars in mid-2003, Chick relates.

Only in America

 Still, other controls vendors have remained standoffish about the PAC name—in part, perhaps, due to its U.S. market origins.

France-based Schneider Electric, whose Modicon brand traces its roots all the way to the 1968 invention of PLCs, did not introduce its first product dubbed a PAC—the mid-range M340—until June of last year, even though earlier Schneider products have offered PAC-like characteristics. That’s because customers until now have been generally happy with the PLC name, say executives at the company’s North American operations, in Palatine, Ill.

And in fact, the Schneider move to the new name is only happening here. “In North America, Schneider Electric is referring to the Modicon M340 as a PAC, because we want our North American customers to know that the M340 has the capabilities that this market associates with a PAC,” says Geoff Walker, director of strategic accounts for the Schneider Electric North American Operating Division. But because the European market “has not put much emphasis on PACs vs. PLCs,” says Walker, the company still uses the term PLC in Europe when referring to the Modicon M340.
At Siemens Energy & Automation Inc., another big automation controls vendor whose parent is based in ...