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

Owning Palette: Single Tone Measurements VIs

Installed With: Sound and Vibration Measurement Suite

Computes idle channel noise power, median noise level, and maximum spur based on scaled signal and frequency range. This VI also computes the signal-to-noise ratio (SNR) measured without a signal, provided you supply a full-scale level. The data type you wire to the scaled signal input determines the polymorphic instance to use.

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

Select an instance SVT Idle Channel Noise (Time) (1 Ch)SVT Idle Channel Noise (Frequency) (1 Ch)

SVT Idle Channel Noise (Time) (1 Ch)

	desired units specifies the engineering units of the returned measurements. idle channel noise units specifies the units for idle channel noise. 0 dB (default) 1 EU^2 rms
	scaled signal [EU] specifies the scaled signal expressed in the selected engineering units. To obtain a properly scaled signal, you can use the SVL Scale Voltage to EU VI or define a virtual channel in National Instruments Measurement & Automation Explorer (MAX). t0 is the start time of the waveform. dt is the time interval in seconds between data points in the waveform. Y contains the data values of the waveform.
	frequency range defines the frequency band of analysis. start frequency specifies the lowest frequency of interest for the analysis band in hertz. Specify a value of -1 to select f0 as the minimum frequency of interest. stop frequency specifies the highest frequency of interest for the analysis band in hertz. The valid range is between 0 and the Nyquist frequency. Specify a value of –1 to select the highest frequency as the maximum frequency of interest.
	full-scale level returns the noise level of the input signal in the specified frequency range.
	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.
	unit labels returns the unit label for each member of desired units. idle channel noise unit label returns a string that corresponds to the selected idle channel noise units.
	complex spectrum returns the complex form of the computed spectrum. complex spectrum returns the complex form of the spectrum. f0 returns the start frequency, in hertz, of the spectrum. df returns the frequency resolution, in hertz, of the spectrum. complex spectrum returns the complex form of the computed spectrum. spectrum info returns information about the spectrum needed by the Spectrum Extended Measurements VIs, the Waterfall Display VIs, the Distortion VIs, and the Single Tone Measurements VIs. Do not modify the spectrum info values.
	idle channel noise returns the aggregate noise power of the input signal in the specified frequency range.
	median noise level returns the noise level of the input signal in the specified frequency range. The median noise level is a measure of the noise floor as computed from the power spectral density (PSD).
	SNR returns the signal-to-noise ratio (SNR) as the ratio between the full-scale level and the idle channel noise.
	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.
	maximum spur returns the frequency and value, in root-mean-square (RMS) engineering units, for the maximum noise spur in the specified frequency range. frequency returns the frequency of the maximum noise spur. value returns the value of the maximum noise spur.
	average noise level [EU / sqrt(Hz)] returns the average noise level of the input signal in the specified frequency range.

SVT Idle Channel Noise (Frequency) (1 Ch)

	desired units specifies the engineering units of the returned measurements. idle channel noise units specifies the units for idle channel noise. 0 dB (default) 1 EU^2 rms
	complex spectrum is the complex form of the computed spectrum. complex spectrum response is the complex form of the spectrum for the response channel. f0 specifies the start frequency, in hertz, of the spectrum. df specifies the frequency resolution, in hertz, of the spectrum. complex spectrum is the complex form of the computed spectrum. spectrum info contains information about the spectrum needed by the Spectrum Extended Measurements VIs, the Waterfall Display VIs, the Distortion VIs, and the Single Tone Measurements VIs. Do not modify the spectrum info values.
	frequency range defines the frequency band of analysis. start frequency specifies the lowest frequency of interest for the analysis band in hertz. Specify a value of -1 to select f0 as the minimum frequency of interest. stop frequency specifies the highest frequency of interest for the analysis band in hertz. The valid range is between 0 and the Nyquist frequency. Specify a value of –1 to select the highest frequency as the maximum frequency of interest.
	full-scale level returns the noise level of the input signal in the specified frequency range.
	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.
	unit labels returns the unit label for each member of desired units. idle channel noise unit label returns a string that corresponds to the selected idle channel noise units.
	complex spectrum returns the complex form of the computed spectrum. complex spectrum returns the complex form of the spectrum. f0 returns the start frequency, in hertz, of the spectrum. df returns the frequency resolution, in hertz, of the spectrum. complex spectrum returns the complex form of the computed spectrum. spectrum info returns information about the spectrum needed by the Spectrum Extended Measurements VIs, the Waterfall Display VIs, the Distortion VIs, and the Single Tone Measurements VIs. Do not modify the spectrum info values.
	idle channel noise returns the aggregate noise power of the input signal in the specified frequency range.
	median noise level returns the noise level of the input signal in the specified frequency range. The median noise level is a measure of the noise floor as computed from the power spectral density (PSD).
	SNR returns the signal-to-noise ratio (SNR) as the ratio between the full-scale level and the idle channel noise.
	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.
	maximum spur returns the frequency and value, in root-mean-square (RMS) engineering units, for the maximum noise spur in the specified frequency range. frequency returns the frequency of the maximum noise spur. value returns the value of the maximum noise spur.
	average noise level [EU / sqrt(Hz)] returns the average noise level of the input signal in the specified frequency range.