SINAD Analyzer VI

SINAD Analyzer 1 Chan

signal in is the input time-domain signal.

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, which is the center frequency and width, used for finding the fundamental frequency tone of the signal.

	approx freq. is the center frequency used in the frequency domain search for the fundamental tone frequency. If set to the default value of –1.0, the tone with the highest amplitude is used as the fundamental tone.
	search is the frequency width, as a percentage of the sampling rate, for the frequency domain search for the fundamental 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 fundamental frequency contains the detected fundamental frequency resulting from searching the frequency domain. Use advanced search to set the frequency search range.

SINAD contains the measured Signal in Noise and Distortion (SINAD) expressed in dB. SINAD is defined as the ratio of the RMS energy of signal in to the RMS energy of signal in less the energy in the fundamental. To compute the THD Plus Noise in dB, simply negate the SINAD in dB.

THD Plus Noise contains the measured total harmonic distortion plus noise. THD Plus Noise is defined as the ratio of the RMS energy of signal in less the energy in the fundamental to the RMS energy of signal in. To compute THD Plus Noise as a percentage, you must multiply it by 100.

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.

SINAD Analyzer N Chan

The multichannel 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.

signals in is the array of input time-domain signals.

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, which is the center frequency and width, used for finding the fundamental frequency tone of the signal.

	approx freq. is the center frequency used in the frequency domain search for the fundamental tone frequency. If set to the default value of –1.0, the tone with the highest amplitude is used as the fundamental tone.
	search is the frequency width, as a percentage of the sampling rate, for the frequency domain search for the fundamental 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 fundamental frequencies is an array containing the detected fundamental frequency resulting from searching the frequency domain for each waveform.

SINAD is an array containing the measured Signal in Noise and Distortion (SINAD) for each waveform expressed in dB. SINAD is defined as the ratio of the RMS energy of the input signal to the RMS energy of the input signal less the energy in the fundamental. To compute the THD Plus Noise in dB, simply negate the SINAD in dB.

THD Plus Noise is an array containing the measured total harmonic distortion plus noise for each waveform.

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.

SINAD Analyzer Details

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

THD Plus Noise in dB is the negative of the SINAD in dB.

Example

Refer to the SINAD Measurement VI in the labview\examples\Signal Processing\Waveform Measurements directory for an example of using the SINAD Analyzer VI.

Open example Find related examples