Computes 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.


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The FFT Power Spectrum VI completes the following steps to compute power spectrum or power spectral density:

  1. Computes the FFT of time signal.
  2. Forms the power spectrum or power spectral density of time signal.
  3. Averages the current power spectrum/power spectral density with the power spectra/power spectral densities computed in previous calls to the VI since the last time the averaging process was restarted.
  4. Returns the averaged power spectrum or power spectral densities in Power Spectrum/PSD.

The single-channel version of this VI can perform single-channel measurements in both one-shot mode, meaning a single call, and continuous mode, meaning multiple calls with history. The single-channel version can perform multichannel measurements only in one-shot mode. If you want to make multichannel measurements in continuous mode, use the multichannel version of this VI.

The single-channel version of this VI maintains internal state information for a single channel only. Calling the single-channel version to process another channel without using the restart averaging control to clear the history results in an unexpected behavior of this VI. The unexpected behavior results from the VI passing the internal state information from one channel to another.

Note The single-channel version of this VI is intended primarily for continuous processing of a single channel. Do not generalize this behavior to the multichannel case and use the single-channel version in a For Loop to continuously process multiple channels by indexing an array of waveforms.