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National Instruments Corporation
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Getting Started with the NI 447
X
This chapter describes the NI 447
X
family of dynamic signal acquisition
devices, which includes the NI PCI-4472, NI PCI-4474, NI PXI-4472, and
NI PXI-4472B. It lists what you need to get started, explains how to unpack
the device, and describes your programming choices.
About the NI 447
X
The NI 447
X
devices are high-performance, high-accuracy analog input
devices that are part of the National Instruments Dynamic Signal
Acquisition/Analysis (DSA) product family. These devices are specifically
designed for demanding dynamic signal acquisition applications.
The NI PCI/PXI-4472 (including the NI PXI-4472B) features eight analog
input (AI) channels, and the NI PCI-4474 has four AI channels. The AI
channels on all NI 447
X
devices are simultaneously sampled at a maximum
rate of 102.4 kS/s with 24-bit resolution and multiple triggering modes,
including external digital triggering. Each AI channel has an independent
software-switchable 4 mA current source for integrated circuit
piezoelectric, also known as
Integral Electronic Piezoelectric
(IEPE),
accelerometers and microphone preamplifiers. The NI PXI-4472B differs
from the other NI 447
X
devices in having a lower cutoff frequency for
AC-coupled input channels. All references to the NI PXI-4472 in this
manual also apply to the NI PXI-4472B unless otherwise noted. Refer to
Appendix A,
, for more details about the NI 447
X
.
The AI circuitry uses oversampling delta-sigma modulating A/D converters
(ADCs). Delta-sigma converters are inherently linear, provide built-in
brick-wall antialiasing filters, and have specifications that exceed other
conventional technology for this application with regard to total harmonic
distortion (THD), signal-to-noise ratio (SNR), and amplitude flatness.
These features help you acquire signals with high accuracy and high
fidelity without introducing noise or out-of-band aliases.
Applications for NI 447
X
devices include audio signal processing and
analysis, acoustics and speech research, sonar, audio frequency test and
measurement, vibration, structural dynamics, and modal analysis, or any
application requiring high-fidelity signal acquisition.
