By John Keller

BOHEMIA, N.Y. — Board designers at the Apex Signal Division of North Atlantic Industries in Bohemia, N.Y., are taking a "restaurant menu" approach to enable systems designers to customize VME and CompactPCI boards with a wide variety of off-the-shelf modules.

The intent of the boards, called the VME 64C1 and CompactPCI 78C1, is not to change their open architectures, but instead to improve system density by placing several different functions on one card — particularly on-board diagnostics, explains Fred Haber, director of marketing at Apex Signal.

Each card contains six independent slots for Apex Signal 5-by-1-inch function modules, which company engineers package as custom-form-factor mezzanine cards.

In addition to on-board diagnostics, functions available on the modules include A-D and D-A converters, synchro-to-digital converters, linear variable displacement transducer (LVDT)-to-digital converters, resistance temperature devices (RTDs), discretes, digital I/O, differential transistor-to-transistor logic (TTL), 420 milliamp on board loop control, and more functions in the future, Haber says.

"The ability to mix and match gives the systems designer tremendous flexibility," Haber says. "If he needs more A-Ds, put another slot in and you're up and running. The card is like a Chinese restaurant menu; he can get maximum density out of what he is looking for."

The growing degree of system automation is the driving force behind the Apex Signal cards, Haber says. "The more automated a system becomes — a tank, ship, or aircraft — the more you require diagnostics to tell you what is wrong, and what is the critical-ness," he says.

"You have fewer people on board, and you don't have a lot of time. It's up to the tank commander, then, to decide to keep on going or turn back. Everything is automated. If there is a problem, where is it? Diagnostics is crucial."

Among the enabling technologies of the boards are digital signal processors (DSPs). Haber says. Each board has two DSPs that do the interfacing with the VME or CompactPCI data bus, and control the individual modules.

"Everyone who sees it falls in love with it, the reason being that as you make the cards more dense, you eliminate cards, open the chassis for spare slots, and in many cases eliminate a whole chassis," Haber says. "It reduces power, weight, cost, and size."

To back up his claim, he says these boards are on the Lockheed Martin Theater High Altitude Area Defense System, the United Defense Future Combat Vehicle, shipboard electronics from Sperry Marine, and test equipment for the Airbus A380 jetliner.

The boards are available in air-cooled or conduction-cooled versions, and operate in two temperature ranges — 0 to 70 degrees Celsius, or -40 to 85° C. Each card can dissipate six to seven Watts.

For more information contact the Apex Signal Division of North Atlantic Industries by phone at 631-567-1100, by post at 170 Wilbur Place, Bohemia, N.Y. 11716, or on the World Wide Web at http://www.naii.com/.