Tone Extraction

LabVIEW SignalExpress

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Tone Extraction

Finds the single tone with the highest amplitude or searches a frequency range you specify to find the single tone with the highest amplitude and returns the frequency, amplitude, and absolute phase for the detected tone. The step also can export Export signals to the Project View.

Parameter

Description

Exported Time Signal

Displays the time signal that Export signals specifies.

Displayed signal—Specifies the signal(s) to display in the preview graph(s). This option appears only when you select a group of signals for the input.
Note If the input signals include scalar values that depend on the values of input waveform signals, you cannot specify to display all signals in the preview graph(s).

Exported Power Spectrum

Displays the power spectrum in decibels that Exported Time Signal specifies.

Autoscale magnitude

Scales the magnitude scale of the power spectrum result graph. The default is to autoscale the magnitude.

Input/Output

Contains the following options:

Input signal—Specifies the signal from which to extract tonal data.
Export time signal—Exports the time signal that Exported Time Signal displays to the Project View.
Export power spectrum—Exports the power spectrum result that Exported Power Spectrum displays to the Project View.

Configuration

Contains the following option:

Measurement Setup and Results—Contains the following options:
- Export signals—Specifies the signal to display on the graphs and optionally export to the Project View. Options include None, Input Signal, Extracted Tone, or Residual Signal, which is the input signal minus the extracted single tone. The default is Input Signal.
- Detected frequency—Returns the frequency of the detected single tone in hertz.
- Detected amplitude—Returns the amplitude of the detected single tone.
- Detected phase (deg)—Returns the phase of the detected single tone in degrees.

Advanced

Contains the following option:

Advanced Measurement Setup—Contains the following options:
- Approximate frequency (Hz)—Specifies the center frequency to use in the frequency-domain search for the single tone. A negative value corresponds to search automatically for the tone with the highest amplitude. The default is –1.
- Search range (% of sample rate)—Specifies the frequency span as a percentage of the sampling rate for the frequency-domain search for the single tone frequency. The default is 0.25%.

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