Data Acquisition Systems Then and Now

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Data Acquisition (often abbreviated as DAQ) has become an industry standard term that refers to almost any type of computer based system comprised of analog and/or digital inputs and outputs. Today most systems are based upon PCs, but there is still a large market for systems based upon other platforms such as VME and PXI as well as those based on proprietary embedded controllers.

It was not that long ago the stereotype of an engineer was someone in a white lab coat watching one or more meters and writing results on a clipboard. The advent of extremely low cost computers, combined with the development of a wide variety of powerful data acquisition interfaces has driven this stereotype farther back in history than black and white movies. Also, most college graduates in science and engineering disciplines have enough programming training and experience to make the programming required for DAQ applications quite straightforward.

There are a wide variety of interfaces used to connect data acquisition hardware to computers. Most popular among these are the PCI bus, Ethernet and USB protocols. In addition to interfaces connecting DAQ systems to standard PCs, there is a rapidly growing market for embedded systems where a program is written and deployed on the data acquisition system itself, allowing it to run standalone.

In the early 1980's, when the PC-based DAQ market was in its infancy, most analog input and output devices offered 12-bit resolution. There were also some lower speed products with greater than 12-bit resolution and a number of high speed products offering resolution in the 8 to 10-bit range. Today, the technology has changed and the standard resolution is 16-bit, with DAQ products offering resolutions up to 24-bit while some of the higher speed, lower resolution products are even challenging the performance of low end digital oscilloscopes.

UEI offers a wide assortment of data acquisition and control products based upon PCI, PXI and Ethernet interfaces. The company's PowerDAQ board level products offer extremely high performance and the line includes the industry's widest assortment of simultaneously sampling boards as well as the highest density (most channels per board) analog output boards. The PowerDNA family of Ethernet-based DAQ interfaces offers an incredible combination of compact, rugged and distributed data acquisition and control cubes.

UEI's UEILogger™ family is a high performance data logger or data recorder. In a standard data acquisition configuration, one or more I/O interface is connected directly to a PC. The I/O is then directly controlled by the PC and all data is stored in the PC, either in memory or on a disk drive. The UEILogger data recorder allows a measurement system to be deployed in a standalone mode, without a permanent (or even temporary) link to a PC. Data acquired is stored in local memory. In the case of the UEILogger, the acquired data is stored on a standard SD card.

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