PC-based Data Acquisition Changes the Way Things are Measured

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PC-based Data Acquisition (often referred to as PC-based DAQ) is a subset of the overall data acquisition and control marketplace. From their roots based in the original Apple II and then the ground breaking IBM PC, the personal computer has continued to become a larger and larger factor in this market. Though there remain systems based on some legacy architectures such as MultiBus and Standard Bus, the PC has come to dominate the CPU end of the market.

As the PC has progressed, so has the PC-based data acquisition market. From the original 8-bit bus included in the original single floppy drive, no hard drive IBM PC, to the latest PCI-Express interfaces built into the latest multi-processor workstations, DAQ has kept the pace. There has never been a wider selection of different ways to automate a measurement, and the PC is at the center of almost all of them.

Only a few years ago, most engineers' idea of data acquisition was standing in front of one or more LED displays and periodically writing down the readings. High speed waveforms were captured by taking a photograph of an oscilloscope screen. All that has changed. The availability of extremely powerful and remarkably inexpensive PCs, combined with the development of a wide variety of powerful data acquisition interfaces has driven this stereotype further 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 bits, with DAQ products offering resolution up to 24-bit resolution while some of the higher speed, lower resolution products are now 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 new 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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