"Convergence," anyone?
Brad Thompson, Contributing Technical Editor -- Test & Measurement World, 7/1/2001
If you're like me, you've puzzled over the meaning of "convergence," a slippery catchword that deserves quotation marks to distinguish it from color-CRT convergence, a relatively ancient test procedure. If you've been reading about "wireless" applications, chances are "convergence" has appeared in every paragraph. Today, most "convergent" products build on cell-phone technology, itself a successful amalgamation of telephones and two-way radios.
Too many convergent products invert Dr. Johnson's description of a dog that walks on its hind legs-we're not surprised these products exist; we're surprised they're not done better. Some converged products, rushed to market in the dot-com boom, test the limits of everyday utility. Once the novelty wears off, will you want to browse the Web on a cell phone's matchbook-size screen?
Successful converged products exist, and clock radios and test equipment provide good examples. By combining timekeeping and communications technologies, someone formed a useful product, a single box that replaced a clock and a radio. Instead of waking to the sound of bells, one could choose music or a news program.
The simplest form of converged test instrument packs several instruments into a common housing to form a specialized test set. This technique traces back to radio's early days. A Rider 1938 Chanalyst, for example, contained a signal generator, signal tracer, and several meters. Each instrument could function on its own, but the combination saved bench space and reduced manufacturing costs.
A logic analyzer and an oscilloscope can share a common display and offer enhanced interoperability. For example, Tektronix's iView instrument closely couples certain features of oscilloscopes and logic analyzers to let you see the same signal as both an analog and a digital waveform.
Convergence can surface unexpectedly. While shopping for a portable multiband receiver, I discovered Alinco's DJ-X2000, a 100 kHz-to-2.15 GHz radio the size of a cell phone. The radio includes a surveillance-device detector, a low-resolution spectrum analyzer, a field-strength meter, and a frequency counter. These aren't precision instruments, but their features sold me on the radio, and already I've used the instruments on my test bench.
Wireless data-acquisition devices have appeared on the market, but where's the clock-multimeter? An easy-to-program DMM could "wake up" every n minutes and capture a measurement. The next day, you could view time-stamped measurements or transfer the data to a PC. When left unattended, a clock-DMM would consume far less power than a PC equipped with a data-acquisition card.
Sometimes, it's difficult to distinguish convergence from its dark side-feature creep-but markets have a way of separating gimmicks from gold. And we'll enjoy watching as they do! T&MW
