For sensors: smarter is better.

Ryan Wynn, a DAQ product manager with National Instruments (Austin, TX; www.ni.com), talks about the difference between "smart" sensors and, well, not-so-smart (i.e., dumb) sensors. Essentially, the smart ones are those that have been defined by a recently passed standard, the IEEE 1451 Smart Transducer Interface Standard. And with a smart one--say a thermal couple--there is all of the information describing the sensor embedded within it, as compared to the dumb one, where the data sheet is a piece of paper. As a practical manner, this means that there is a "plug-and-play" capability: calibration and linearization are automatic. "No longer is it necessary to have an army of technicians out there putting in all of these sensors and then calibrating them." Because the detail on the calibration for a particular sensor is much more detailed than that found on the paper data sheets, this also means that there is improved accuracy: the information that's obtained by the sensor is better. With non-smart sensors, the data sheets are generally generic, not specific as is the case with the IEEE 1451 devices (colloquially referred to as "TEDS sensors," with that acronym coming from "Transducer Electronic Data Sheet.") Among the information found on a TEDS memory chip (EEPROM) are: sensor manufacturer, serial number, measurement range, and calibration information.

National Instruments, for example, is a company that offers software and hardware to create virtual instrumentation for a variety of testing requirements. When asked how the smart sensors relate to those systems, Wynn answers that data acquisitions systems can be more readily deployed. That is, an NVH system will include such sensors as accelerometers, strain gages, force sensors, etc., and multiples of each. There could be some 200 channels involved. Wynn explains that with the smart sensors, this is a whole lot easier than in the past, with a couple of technicians, say, "plugging in the sensors like peripherals for a PC."

While this is well and good for those who are in the market for new sensors, Wynn admits that auto companies have tens of thousands of legacy sensors that aren't smart. So what to do? Apparently, even though TEDS devices provide the means to have faster setups and provide better accuracy, the ROI of replacing all of the existing sensors with new ones doesn't make economic sense. Wynn says that there is another "flavor" of TEDS: Virtual TEDS. "Instead of having a TEDS binary file in EEPROM on a chip," he says, "we have a sensor partner program. They've supplied binary TEDS files that we store in a database. So the user can download the TEDS files and use it inside LabView 7.1," a recently launched graphical development product to create test, measurement and control applications for hardware systems ranging from high-performance modular instruments to real-time data acquisition systems and handheld devices.

Wynn admits, "Sensors haven't changed for a long time." This time, however, the change is notable.--GSV