Extract Single Tone Information VI

Owning Palette: Waveform Measurements VIs

Requires: Full Development System

Takes 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.

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Use the pull-down menu to select an instance of this VI.

Select an instance Extract Single Tone Information 1 ChanExtract Single Tone Information 1 Chan (CDB)Extract Single Tone Information N ChanExtract Single Tone Information N Chan (CDB)

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Extract Single Tone Information 1 Chan

	time signal in is the time-domain waveform.
	export mode selects the source of the signal and spectrum to export to exported signals. 0 none—Fastest computation 1 input signal—Input signal only 2 detected signal—Single tone 3 residual signal—Signal minus tone
	error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
	advanced search controls the frequency domain search area, center frequency, and width. You use advanced search for narrowing the single tone search range. approx freq. is the center frequency used of the frequency domain search for the single tone. The default is –1.0, which means the VI searches the tone in the full frequency range of (0, Fs/2). search is the frequency width, as a percentage of the sampling rate, for the frequency domain search for the single tone frequency.
	exported signals contains the signals specified by export mode. exported time signal is the waveform containing the exported time signal as selected by export mode. exported spectrum (dB) is the spectrum of the exported time signal as selected by export mode. f0 returns the start frequency, in hertz, of the spectrum. df returns the frequency resolution, in hertz, of the spectrum. dB Spectrum (Hann) is the magnitude spectrum of the (Hanning) windowed input signal, expressed in dB relative to 1.0 Vrms^2 for input signals in units of volts (V).
	detected frequency is the frequency of the detected single tone in Hz.
	detected amplitude is the peak amplitude of the detected single tone.
	detected phase is the phase of the detected single tone in degrees. Use the Wrap Angle VI to change the units of detected phase. Wire detected phase to the angle in input on the Wrap Angle VI, and select degree in, degree out or degree in, radians out for the angle units input.
	error out contains error information. This output provides standard error out functionality.
	measurement info returns information about your measurement, mainly warnings for inconsistencies in your input signal. uncertainty is reserved for future use. Warning is TRUE if a warning is generated during processing. comments contains a warning message when Warning is TRUE.

Extract Single Tone Information 1 Chan (CDB)

	time signal in is the time-domain waveform.
	export mode selects the source of the signal and spectrum to export to exported signals. 0 none—Fastest computation 1 input signal—Input signal only 2 detected signal—Single tone 3 residual signal—Signal minus tone
	error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
	advanced search controls the frequency domain search area, center frequency, and width. You use advanced search for narrowing the single tone search range. approx freq. is the center frequency used of the frequency domain search for the single tone. The default is NaN, which means the VI searches the tone in the full frequency range of (–Fs/2, Fs/2). search is the frequency width, as a percentage of the sampling rate, for the frequency domain search for the single tone frequency.
	exported signals contains the signals specified by export mode. exported time signal is the waveform containing the exported time signal as selected by export mode. exported spectrum (dB) is the spectrum of the exported time signal as selected by export mode. f0 returns the start frequency, in hertz, of the spectrum. df returns the frequency resolution, in hertz, of the spectrum. dB Spectrum (Hann) is the magnitude spectrum of the (Hanning) windowed input signal, expressed in dB relative to 1.0 Vrms^2 for input signals in units of volts (V).
	detected frequency is the frequency of the detected single tone in Hz.
	detected amplitude is the peak amplitude of the detected single tone.
	detected phase is the phase of the detected single tone in degrees. Use the Wrap Angle VI to change the units of detected phase. Wire detected phase to the angle in input on the Wrap Angle VI, and select degree in, degree out or degree in, radians out for the angle units input.
	error out contains error information. This output provides standard error out functionality.
	measurement info returns information about your measurement, mainly warnings for inconsistencies in your input signal. uncertainty is reserved for future use. Warning is TRUE if a warning is generated during processing. comments contains a warning message when Warning is TRUE.

Extract Single Tone Information N Chan

The waveform array input should be the result of a multichannel acquisition where each element of the array of waveforms is a distinct and separate channel of data.

	time signals in is an array of time-domain waveforms.
	export mode selects the source of the signal and spectrum to export to exported signals. 0 none—Fastest computation 1 input signal—Input signal only 2 detected signal—Single tone 3 residual signal—Signal minus tone
	error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
	advanced search controls the frequency domain search area, center frequency, and width. You use advanced search for narrowing the single tone search range. approx freq. is the center frequency used of the frequency domain search for the single tone. The default is –1.0, which means the VI searches the tone in the full frequency range of (0, Fs/2). search is the frequency width, as a percentage of the sampling rate, for the frequency domain search for the single tone frequency.
	exported signals is an array of exported signals. exported time signal is the waveform containing the exported time signal as selected by export mode. exported spectrum (dB) is the spectrum of the exported time signal as selected by export mode. f0 returns the start frequency, in hertz, of the spectrum. df returns the frequency resolution, in hertz, of the spectrum. dB Spectrum (Hann) is the magnitude spectrum of the (Hanning) windowed input signal, expressed in dB relative to 1.0 Vrms^2 for input signals in units of volts (V).
	detected frequencies is an array of frequencies of the detected single tone in Hz for each waveform.
	detected amplitudes is an array of peak amplitudes of the detected single tone for each waveform.
	detected phases is an array of phases of the detected single tone in degrees for each waveform. Use the Wrap Angle VI to change the units of detected phases. Wire detected phases to the angle in input on the Wrap Angle VI, and select degree in, degree out or degree in, radians out for the angle units input.
	error out contains error information. This output provides standard error out functionality.
	measurements info is an array that returns information about your measurement, mainly warnings for inconsistencies in your input signal. uncertainty is reserved for future use. Warning is TRUE if a warning is generated during processing. comments contains a warning message when Warning is TRUE.

Extract Single Tone Information N Chan (CDB)

	time signals in is an array of time-domain waveforms.
	export mode selects the source of the signal and spectrum to export to exported signals. 0 none—Fastest computation 1 input signal—Input signal only 2 detected signal—Single tone 3 residual signal—Signal minus tone
	error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
	advanced search controls the frequency domain search area, center frequency, and width. You use advanced search for narrowing the single tone search range. approx freq. is the center frequency used of the frequency domain search for the single tone. The default is NaN, which means the VI searches the tone in the full frequency range of (–Fs/2, Fs/2). search is the frequency width, as a percentage of the sampling rate, for the frequency domain search for the single tone frequency.
	exported signals is an array of exported signals. exported time signal is the waveform containing the exported time signal as selected by export mode. exported spectrum (dB) is the spectrum of the exported time signal as selected by export mode. f0 returns the start frequency, in hertz, of the spectrum. df returns the frequency resolution, in hertz, of the spectrum. dB Spectrum (Hann) is the magnitude spectrum of the (Hanning) windowed input signal, expressed in dB relative to 1.0 Vrms^2 for input signals in units of volts (V).
	detected frequencies is an array of frequencies of the detected single tone in Hz for each waveform.
	detected amplitudes is an array of peak amplitudes of the detected single tone for each waveform.
	detected phases is an array of phases of the detected single tone in degrees for each waveform. Use the Wrap Angle VI to change the units of detected phases. Wire detected phases to the angle in input on the Wrap Angle VI, and select degree in, degree out or degree in, radians out for the angle units input.
	error out contains error information. This output provides standard error out functionality.
	measurements info is an array that returns information about your measurement, mainly warnings for inconsistencies in your input signal. uncertainty is reserved for future use. Warning is TRUE if a warning is generated during processing. comments contains a warning message when Warning is TRUE.

Extract Single Tone Information Details

A real tone signal can be expressed as shown in the following equation:

where A, f, and are the amplitude, frequency, and phase of the tone signal, respectively, and F_s is the sample rate in samples per second of the input waveform signal.

A complex tone signal can be expressed as shown in the following equation:

where A, f, and are the amplitude, frequency, and phase of the tone signal, respectively, and F_s is the sample rate in samples per second of the input waveform signal.

This VI is designed to process a single channel or multiple channels continuously, typically from within a For Loop or a While Loop.

For a real signal, the frequency range is (min frequency, max frequency) = (0, F_s/2). For a complex signal, the frequency range is (min frequency, max frequency) = (–F_s/2, F_s/2).

Examples

Refer to the following VIs for examples of using the Extract Single Tone Information VI:

• Correct for MIO inter-channel delay (continuous) VI: labview\examples\Signal Processing\Waveform Conditioning

   Open example  Find related examples

• Single Tone Measurements VI: labview\examples\Signal Processing\Waveform Measurements

   Open example  Find related examples

• Complex Single Tone Measurements VI: labview\examples\Signal Processing\Waveform Measurements

   Open example  Find related examples