Swept Sine FRF (DAQmx)
PrintOverview
This VI performs a swept sine measurement to obtain the root-mean-square (RMS) levels of the acquired stimulus and response, the frequency response of the device under test (DUT), and the harmonic distortion on the response channel. You specify the source and measurement parameters, and the swept sine VIs handle all the DAQ-specific controls required to perform the measurement. You have direct control over the source, input, averaging, and display parameters. You also specify the engineering units to use for the swept sine measurements.
You can view the time records of the acquired stimulus and response signals. From these graphs, you can see that the transition to the next test frequency always occurs at a zero crossing to minimize non-linear disturbances to the DUT. The RMS levels, frequency response, and harmonic distortion are shown on different tabs. This program is a shipping example VI included with the NI Sound and Vibration Measurement Suite and NI Sound and Vibration Toolkit.
This Virtual Instrument is designed to work with data acquisition hardware from National Instruments. To find compatible hardware for this application, visit ni.com/soundandvibration.
This software is written in LabVIEW, a graphical programming language designed for scientists and engineers. For more information about LabVIEW, visit ni.com/labview.
Sound and Vibration Developers Library
The NI Sound and Vibration Developers Library is your one-stop online resource for learning about and downloading code for acoustic analysis, machine diagnostics and audio test functions. On this page, you will find links to detailed tutorials, application notes, example programs, and analysis function descriptions.
More information on National Instruments signal processing can be found at the Signal Processing Resource Center.
Downloads
Filename: swept_sine_frf_daqmx.vi
Requirements: View
Front Panel
This is a picture of the VI's front panel. To view the block diagram and additional documentation, download the attached file.
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Requirements
Filename: swept_sine_frf_daqmx.vi
Software Requirements
Application Software: LabVIEW Full Development System 8.2
Toolkits and Add-Ons: LabVIEW Sound and Vibration Toolset 5.0
Hardware Requirements
Hardware Group: Dynamic Signal Analyzers (DSA)
Driver: NI-DAQmx 8.3
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Legal
This example program (this "program") was developed by a National Instruments ("NI") Applications Engineer. Although technical support of this program may be made available by National Instruments, this program may not be completely tested and verified, and NI does not guarantee its quality in any way or that NI will continue to support this program with each new revision of related products and drivers. THIS EXAMPLE PROGRAM IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND AND SUBJECT TO CERTAIN RESTRICTIONS AS MORE SPECIFICALLY SET FORTH IN NI.COM'S TERMS OF USE (http://ni.com/legal/termsofuse/unitedstates/us/).