You are here: NI Home > Support > Product Reference > Manuals > Sound and Vibration Measurement Suite 7.0 Help

Owning Palette: Spectrum Extended Measurements VIs

Installed With: Sound and Vibration Measurement Suite

Extracts the value of the spectrum at the specified frequency. Use the frequency coercion control to specify how the frequency should be coerced if it does not exactly coincide with a frequency line. This VI operates on any real-valued spectrum.

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

Select an instance SVFA Get Spectrum Value (1 Ch)SVFA Get Spectrum Value (N Ch)

SVFA Get Spectrum Value (1 Ch)

	spectrum specifies the abscissa scaling and the magnitude of the spectrum. x0 specifies the start frequency or order of the spectrum. dx specifies the frequency or order resolution of the spectrum. magnitude specifies the magnitude of the spectrum.
	frequency [Hz] specifies the frequency of interest in hertz.
	frequency coercion specifies whether the specified frequency [Hz] will be coerced to the closest, next higher, or next lower spectrum frequency; or whether the spectrum will be interpolated to satisfy the specified frequency [Hz]. 0 coerce to nearest (default) 1 coerce to next highest 2 coerce to next lowest 3 interpolate
	spectrum info specifies properties of the computed spectrum. The properties contained in spectrum info include channel name, spectrum type, spectrum scale as linear or dB, applied window, window size, FFT size, units, x-axis units, dB reference, applied weighting, peak units, and spectral density. Note  spectrum info must be connected when performing extended measurements. Do not modify the spectrum info values.
	error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use exception control to treat what is normally an error as no error or to treat a warning as an error. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node. status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE. code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
	spectrum value returns the value of the spectrum at the returned actual frequency.
	unit label returns the selected engineering units.
	actual frequency [Hz] returns the coerced frequency corresponding to the returned spectrum value.
	frequency label returns a string containing the coerced frequency.
	error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error. status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

SVFA Get Spectrum Value (N Ch)

	spectra specifies the data for each spectrum. spectrum specifies the abscissa scaling and the magnitude of the spectrum. x0 specifies the start frequency or order of the spectrum. dx specifies the frequency or order resolution of the spectrum. magnitude specifies the magnitude of the spectrum.
	frequency [Hz] specifies the frequency of interest in hertz.
	frequency coercion specifies whether the specified frequency [Hz] will be coerced to the closest, next higher, or next lower spectrum frequency; or whether the spectrum will be interpolated to satisfy the specified frequency [Hz]. 0 coerce to nearest (default) 1 coerce to next highest 2 coerce to next lowest 3 interpolate
	spectrum info specifies properties of the computed spectrum. The properties contained in spectrum info include channel name, spectrum type, spectrum scale as linear or dB, applied window, window size, FFT size, units, x-axis units, dB reference, applied weighting, peak units, and spectral density. Note  spectrum info must be wired when performing extended measurements. Do not modify the spectrum info values.
	error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use exception control to treat what is normally an error as no error or to treat a warning as an error. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node. status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE. code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.
	spectra values returns the values of the spectra at the returned actual frequencies.
	unit labels returns the unit label for each channel.
	actual frequencies [Hz] returns the coerced frequencies corresponding to the returned spectra values.
	frequency labels returns an array of strings containing the coerced frequencies.
	error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error. status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred. code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code. source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.