Tone Measurements

Finds 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.


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Dialog Box Options

Option Description
Single Tone Measurements Contains the following options:
  • Amplitude—

    Calculates the amplitude of the detected single tone in volts peak (Vp).

  • Frequency—

    Calculates the frequency of the detected single tone in Hertz.

  • Phase—

    Calculates the phase of the detected single tone in degrees.
Search for Specific Frequency Contains the following options:
  • Approximate frequency (Hz)—

    Center frequency to use in the frequency domain search for the single tone. The default is 10. This option is available only when you place a checkmark in the Search for Specific Frequency checkbox.

  • Search (+/- % of approx. freq.)—

    Frequency width, as a percentage of the sampling rate, for the frequency domain search for the single tone frequency. The default is 5. This option is available only when you place a checkmark in the Search for Specific Frequency checkbox.
Results

Displays the measurements you configured this Express VI to perform and the calculated values of those measurements. You can click any measurement listed in the Measurement column, and the corresponding value or plot appears in the Result Preview graph.
Input Signal

Displays the input signal.

If you wire data to the Express VI and run it, Input Signal displays real data. If you close and reopen the Express VI, Input Signal displays sample data until you run the Express VI again.
Result Preview

Displays a preview of the measurement. The Result Preview plot indicates the value of the selected measurement with a dotted line.

If you wire data to the Express VI and run the VI, Result Preview displays real data. If you close and reopen the Express VI, Result Preview displays sample data until you run the VI again. If the cutoff frequency values are invalid, Result Preview does not display valid data.
Approximate frequency (Hz)

Center frequency to use in the frequency domain search for the single tone. The default is 10. This option is available only when you place a checkmark in the Search for Specific Frequency checkbox.

Inputs/Outputs

  • cexpdynwdt.png Signals —

    Contains the input signal or signals.

  • cerrcodeclst.png error in (no error) —

    Describes error conditions that occur before this node runs.

  • ierrcodeclst.png error out —

    Contains error information. This output provides standard error out functionality.

  • iexpdynwdt.png Phase —

    Returns the phase of the detected single tone in degrees.

  • iexpdynwdt.png Frequency —

    Returns the frequency of the detected single tone in Hertz.

  • iexpdynwdt.png Amplitude —

    Returns the amplitude of the detected single tone in volts peak (Vp).

    • Examples

    Refer to the following example files included with LabVIEW.

    • labview\examples\Express VIs\Express VI - Filter.vi