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Waveform Measurements VIs

LabVIEW 2013 Help

Edition Date: June 2013

Part Number: 371361K-01

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Owning Palette: Analog Waveform VIs and Functions, Signal Processing VIs

Requires: Full Development System. This topic might not match its corresponding palette in LabVIEW depending on your operating system, licensed product(s), and target.

Use the Waveform Measurements VIs to perform common time and frequency domain measurements, such as DC, RMS, Tone Frequency/Amplitude/Phase, Harmonic Distortion, SINAD, and Averaged FFT Measurements.

Note  The Waveform Measurements VIs presently do not accept waveforms that contain complex data.

The VIs on this palette can return waveform error codes. In addition, the VIs on this palette return an error if an input waveform has a dt less than or equal to zero.

Palette ObjectDescription
Amplitude and Level MeasurementsPerforms voltage measurements on a signal.
Amplitude and LevelsReturns the amplitude, high state level, and low state level of a waveform or an array of waveforms. Wire data to the signal in input to determine the polymorphic instance to use or manually select the instance.

Averaged DC-RMSCalculates the DC and RMS values of an input waveform or array of waveforms. This VI is similar to the Basic Averaged DC-RMS VI, but this VI gives more precise control over the individual DC and RMS calculations.
Basic Averaged DC-RMSCalculates the DC and RMS values of an input waveform or array of waveforms. This VI is similar to the Averaged DC-RMS VI, but this VI returns only one DC value and one RMS value per input waveform.
Cross Spectrum (Mag-Phase)Computes the averaged cross power spectrum of the input signals. Results are returned as magnitude and phase.
Cross Spectrum (Real-Im)Computes the averaged cross power spectrum of the input signals. Results are returned as real and imaginary parts.
Cycle Average and RMSReturns the average and RMS levels of a selected cycle of a periodic waveform or an array of periodic waveforms. Wire data to the signal in input to determine the polymorphic instance to use or manually select the instance.

Distortion MeasurementsPerforms distortion measurements on a signal, such as tone analysis, total harmonic distortion (THD), and signal in noise and distortion (SINAD).
Dual Channel Spectral MeasurementMeasures the frequency response of the input signals and the coherence based on the current and previous input signals. This Express VI returns results such as Magnitude, Phase, Coherence, Real, and Imaginary.
Extract Multiple Tone InformationReturns the frequency, amplitude, and phase for each signal tone whose amplitude exceeds a specified threshold. Wire data to the time signal in input to determine the polymorphic instance to use or manually select the instance.
Extract Single Tone InformationTakes a signal in, finds the single tone with the highest amplitude or searches a specified frequency range, and returns the single tone frequency, amplitude, and phase. The input signal can be real or complex and single-channel or multichannel. Wire data to the time signal in input to determine the polymorphic instance to use or manually select the instance.

FFT Power Spectrum and PSDComputes the averaged auto power spectrum of time signal. Wire data to the time signal input to determine the polymorphic instance to use or manually select the instance.
FFT Spectrum (Mag-Phase)Computes the averaged FFT spectrum of time signal. This VI returns the FFT results as magnitude and phase. Wire data to the time signal input to determine the polymorphic instance to use or manually select the instance.

FFT Spectrum (Real-Im)Computes the averaged FFT spectrum of time signal. This VI returns the FFT results as real and imaginary parts. Wire data to the time signal input to determine the polymorphic instance to use or manually select the instance.
Frequency Response Function (Mag-Phase)Computes the frequency response and the coherence based on the input signals. Results are returned as magnitude, phase, and coherence.
Frequency Response Function (Real-Im)Computes the frequency response and the coherence based on the input signals. Results are returned as real part, imaginary part, and coherence.
Harmonic Distortion AnalyzerTakes a signal in and performs a full harmonic analysis, including measuring the fundamental frequency tone and harmonics, and returning the fundamental frequency, all harmonic amplitude levels, and the total harmonic distortion (THD). Wire data to the signal in input to determine the polymorphic instance to use or manually select the instance.

Pulse MeasurementsAccepts a periodic waveform or an array of periodic waveforms and returns the period, pulse duration (pulse width), duty cycle (duty factor), and pulse center of a selected pulse and period. Wire data to the signal in input to determine the polymorphic instance to use or manually select the instance.

SINAD AnalyzerTakes a signal in and performs a full Signal in Noise and Distortion (SINAD) analysis, including measuring the fundamental frequency tone and returning the fundamental frequency and SINAD level in dB. Wire data to the signal in input to determine the polymorphic instance to use or manually select the instance.

Spectral MeasurementsPerforms FFT-based spectral measurements, such as the averaged magnitude spectrum, power spectrum, and phase spectrum on a signal.
Timing and Transition MeasurementsPerforms timing and transition measurements, such as frequency, period, or duty cycle, on a signal, usually a pulse.
Tone MeasurementsFinds the single tone with the highest amplitude or searches a specified frequency range to find the single tone with the highest amplitude. You also can find the frequency and phase for a single tone.
Transition MeasurementsAccepts an input signal of a single waveform or an array of waveforms and measures the transition duration (rise or fall time), slew rate, undershoot, and overshoot of a selected positive or negative transition in each waveform. Wire data to the signal in input to determine the polymorphic instance to use or manually select the instance.



SubpaletteDescription
Waveform Monitoring VIsUse the Waveform Monitoring VIs to analyze the waveforms for trigger points, to search for peaks, and to perform limit mask testing.

 

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