National Instruments Introduces Highest-Accuracy Multifunction Data Acquisition Devices with USB Connectivity

NI USB-6281 and USB-6289 Increase Functionality with 18-bit Resolution
March 2008 – National Instruments today announced a new line of M Series USB data acquisition (DAQ) devices with 18-bit analog input accuracy at sampling rates up to 625 kS/s. The NI USB-6281 and USB-6289 feature an 18-bit ADC, which provides a 4X increase in resolution over traditional 16-bit devices, equivalent to more than 5½ digits of resolution for DC measurements. These devices also offer enhanced analog output channels that feature programmable range and offset settings. In addition to standard screw terminal or mass termination connectivity options, board-only OEM versions are also available for integration with embedded systems and include 34- and 50-pin insulation-displacement connectors (IDC) for easy board mating.

To ensure accuracy at all available sampling rates, these devices incorporate the NI-PGIA 2 custom amplifier and NI-MCal self-calibration to minimize settling time and guarantee maximum accuracy. An onboard lowpass filter can be programmatically enabled to further improve measurement accuracy by eliminating high frequency noise. With the NI USB-628x devices, engineers can deliver an absolute accuracy of 980 µV at a range of ±10 V and 28 µV at a range of ±100 mV at a sampling rate of up to 625 kS/s.

The USB-6281 features 16 single-ended (SE) and eight differential input (DI) analog input channels, two analog output channels and 24 digital I/O (DIO) channels, while the USB-6289 features 32 SE and 16 DI analog input channels, four analog output channels and 48 DIO channels. Both devices offer 18-bit analog inputs at up to 625 kS/s (500 kS/s when scanning) and 16-bit analog output at 833 kS/s. High-accuracy USB-628x devices also provide enhanced waveform generation. Engineers now can define custom offset and range settings for analog output and maximize the 16 bits of output resolution around a fixed DC offset to generate a more accurate representation of small signals and increase the accuracy of analog waveforms.

High-accuracy NI M Series multifunction DAQ devices are ideal for applications including device test and characterization and for sensor and signal measurements requiring instrument-class accuracy. Applications that can now benefit from the higher accuracy include scientific instrumentation such as geological monitoring, materials analysis, environmental sensing, calorimetry, optics, spectroscopy, structural sensing and gas detection, along with medical device instrumentation such as heart rate monitoring. USB-628x devices are also ideal for electronics characterization and research.

Unlike typical multifunction USB data acquisition devices, NI M Series USB DAQ devices incorporate NI signal streaming, a patent-pending technology that provides multiple bidirectional high-speed data streams over USB. NI signal streaming, combined with the error correction, noise rejection, power management and power distribution inherent to the USB protocol, yields a flexible, secure and reliable bus. Without NI signal streaming, a multifunction data acquisition device can sustain only a single high-speed data stream, effectively making it a single-function device.

The new USB-628x devices are shipped with NI-DAQmx driver software and NI LabVIEW SignalExpress LE, an interactive measurement workbench for quickly acquiring, analyzing and presenting data without additional programming. The NI-DAQmx driver also provides time-saving features such as code generation for both the LabVIEW graphical development environment and text-based languages such as ANSI C/C++, C#, Visual Basic .NET and Visual Basic 6.0; more than 3,000 measurement examples; device simulation; and connection diagrams.