OAT Full Spectrum VI

OAT Full Spectrum VI

Owning Palette: Order Analysis VIs

This VI computes the full spectrum of a probe pair. The full spectrum provides information on the amplitude of vibration as well as the orbit eccentricity and direction of precession for each frequency/order component.

Minimum Data Requirements
This function requires a minimum amount of orbit/timebase plot data before an output will be returned. window and view will affect the amount of data required before an output is returned.

Details  

OAT Full Spectrum (Orbit Plot)

	orbit/timebase plot specifies the buffered orbit or timebase data. This data type is identical to orbit plot and timebase plot. orbit/timebase plot attribute includes direction information. The number of revolutions contained in orbit/timebase plot determines the order resolution in the output full spectrum. probe x specifies the amplitude of probe X. probe y specifies the amplitude of probe Y. reference specifies the time reference of the probe X and probe Y. plot type specifies the type of the input orbit or timebase plot. The default is filtered plot. 0 Filtered Plot (default) 1 Unfiltered Plot attribute specifies additional information about the plot. LabVIEW uses this information to display the data properly and to perform extended measurements.
	window (Hanning) is the time-domain window to apply to the even-angle signal. The default window is Hanning. 0 Rectangle 1 Hanning (default) 2 Hamming 3 Blackman-Harris 4 Exact Blackman 5 Blackman 6 Flat Top 7 4 Term B-Harris 8 7 Term B-Harris 9 Low Sidelobe 11 Blackman Nutall 30 Triangle 31 Bartlett-Hanning 32 Bohman 33 Parzen 34 Welch 60 Kaiser 61 Dolph-Chebyshev 62 Gaussian
	view specifies how the different results from this VI are returned. view allows you to choose whether magnitude results are displayed in dB, phase results are unwrapped, and phase results are converted from radians to degrees. dB On specifies if results are expressed in decibels. The default is FALSE. unwrap phase specifies whether to unwrap the phase. Unwrapping eliminates discontinuities that have an absolute value greater than pi. The default is FALSE, meaning the phase is not unwrapped. When unwrap phase is TRUE, the phase is unwrapped. convert to degree specifies whether the phase results are converted from radians to degrees. The default is TRUE, which means that results are expressed in degrees.
	error in describes error conditions that occur before this node runs. With the following exception, this input provides standard error in functionality. This node runs normally even if an error occurred before this node runs.
	full spectrum returns the forward and reverse discrete order spectra. The full spectrum is the spectrum of the orbit obtained from a sensor pair. forward returns the forward component of the full spectrum. The forward component is the orbit with precession in the same direction as the direction of shaft rotation. reverse returns the reverse component of the full spectrum. The reverse component is the orbit with precession in the opposite direction as the direction of shaft rotation.
	phase lag returns the phase lag (between probes X and Y) versus order.
	phase unit label returns the unit label for the selected phase units.
	spectrum info returns information about the spectrum needed by the Spectrum Extended Measurements VIs, the Display VIs, and the Tone and Distortion VIs. Note  You must wire spectrum info when performing extended measurements. Do not modify the spectrum info values. If you want to view the information, you can right-click the spectrum info wire and select Custom Probe»Spectrum Info from the shortcut menu.
	error out contains error information. With the following exception, this output provides standard error out functionality. If the value of error in is no error, this VI contains error information that corresponds to the error code input.

OAT Full Spectrum (2 Ch Even-Angle Signal)

	rotation direction specifies the direction in which the shaft rotates. The default is counterclockwise. 0 CCW (default)—Counterclockwise 1 CW—Clockwise
	even-angle signals specifies the even-angle resampled data. even-angle signals are synchronous to the rotational speed with a constant number of samples per revolution. Index 0 should correspond with probe X, and Index 1 should correspond to probe Y. r0 specifies the starting index value for counting revolutions. dr specifies the revolution interval between two sequential samples. Y specifies the value of the even-angle-spaced sample in a scaled engineering unit.
	even-angle channel info specifies information that you can pass to another VI about the measurement configuration for even-angle signal. Index 0 should correspond with probe X, and Index 1 should correspond to probe Y. Note  You must wire even-angle channel info when performing extended measurements. Do not modify the even-angle channel info values. If you want to view the information, you can create a custom probe.
	window (Hanning) is the time-domain window to apply to the even-angle signal. The default window is Hanning. 0 Rectangle 1 Hanning (default) 2 Hamming 3 Blackman-Harris 4 Exact Blackman 5 Blackman 6 Flat Top 7 4 Term B-Harris 8 7 Term B-Harris 9 Low Sidelobe 11 Blackman Nutall 30 Triangle 31 Bartlett-Hanning 32 Bohman 33 Parzen 34 Welch 60 Kaiser 61 Dolph-Chebyshev 62 Gaussian
	block size specifies the block size of the even-angle signal this VI uses to compute the full spectrum. The default is -1.
	view specifies how the different results from this VI are returned. view allows you to choose whether magnitude results are displayed in dB, phase results are unwrapped, and phase results are converted from radians to degrees. dB On specifies if results are expressed in decibels. The default is FALSE. unwrap phase specifies whether to unwrap the phase. Unwrapping eliminates discontinuities that have an absolute value greater than pi. The default is FALSE, meaning the phase is not unwrapped. When unwrap phase is TRUE, the phase is unwrapped. convert to degree specifies whether the phase results are converted from radians to degrees. The default is TRUE, which means that results are expressed in degrees.
	error in describes error conditions that occur before this node runs. With the following exception, this input provides standard error in functionality. This node runs normally even if an error occurred before this node runs.
	averaging parameters is a cluster that defines how the averaging is computed. The specifications of the parameters include the type of averaging, the type of weighting, and the number of averages. averaging mode specifies the averaging mode. 0 No averaging (default) 1 Vector averaging 2 RMS averaging 3 Peak hold weighting mode specifies the weighting mode for RMS and vector averaging. 0 Linear 1 Exponential (default) number of averages specifies the number of averages used for RMS and vector averaging. If weighting mode is exponential, the averaging process is continuous. If weighting mode is linear, the averaging process stops after this VI computes the selected number of averages.
	restart averaging specifies if the selected averaging process has to be restarted. The default is FALSE. When you call this VI for the first time, the averaging process restarts automatically.
	new spectrum available returns TRUE if order power spectrum contains a new measurement. When you wire this output value to the selector terminal of a Case structure, you can perform subsequent measurements or display this output value in the TRUE case of the Case structure.
	full spectrum returns the forward and reverse discrete order spectra. The full spectrum is the spectrum of the orbit obtained from a sensor pair. forward returns the forward component of the full spectrum. The forward component is the orbit with precession in the same direction as the direction of shaft rotation. reverse returns the reverse component of the full spectrum. The reverse component is the orbit with precession in the opposite direction as the direction of shaft rotation.
	magnitude unit label returns the unit of the frequency response magnitude.
	phase lag returns the phase lag (between probes X and Y) versus order.
	phase unit label returns the unit label for the selected phase units.
	spectrum info returns information about the spectrum needed by the Spectrum Extended Measurements VIs, the Display VIs, and the Tone and Distortion VIs. Note  You must wire spectrum info when performing extended measurements. Do not modify the spectrum info values. If you want to view the information, you can right-click the spectrum info wire and select Custom Probe»Spectrum Info from the shortcut menu.
	error out contains error information. With the following exception, this output provides standard error out functionality. If the value of error in is no error, this VI contains error information that corresponds to the error code input.
	averages completed returns the number of averages completed by the VI at that time.
	averaging done returns TRUE when averages completed is greater than or equal to the number of averages specified in averaging parameters. Otherwise, averaging done returns FALSE. averaging done is always TRUE if the selected averaging mode is No averaging.

OAT Full Spectrum (1 Pair Waveforms)

	rotation direction specifies the direction in which the shaft rotates. The default is counterclockwise. 0 CCW (default)—Counterclockwise 1 CW—Clockwise
	scaled signal X [EU] specifies the scaled signal expressed in the selected engineering units. scaled signal X [EU] is generally the stimulus or excitation signal in dual-channel measurements. t0 specifies the start time of the waveform. dt specifies the time interval in seconds between data points in the waveform. Y specifies the data values of the waveform.
	scaled signal Y [EU] specifies the scaled signal expressed in the selected engineering units. scaled signal Y [EU] is generally the response signal in dual-channel measurements. t0 specifies the start time of the waveform. dt specifies the time interval in seconds between data points in the waveform. Y specifies the data values of the waveform.
	window (Hanning) is the time-domain window to apply to the time signal. The default window is Hanning. 0 Rectangle 1 Hanning (default) 2 Hamming 3 Blackman-Harris 4 Exact Blackman 5 Blackman 6 Flat Top 7 4 Term B-Harris 8 7 Term B-Harris 9 Low Sidelobe 11 Blackman Nutall 30 Triangle 31 Bartlett-Hanning 32 Bohman 33 Parzen 34 Welch 60 Kaiser 61 Dolph-Chebyshev 62 Gaussian
	view specifies how the different results from this VI are returned. view allows you to choose whether magnitude results are displayed in dB, phase results are unwrapped, and phase results are converted from radians to degrees. dB On specifies if results are expressed in decibels. The default is FALSE. unwrap phase specifies whether to unwrap the phase. Unwrapping eliminates discontinuities that have an absolute value greater than pi. The default is FALSE, meaning the phase is not unwrapped. When unwrap phase is TRUE, the phase is unwrapped. convert to degree specifies whether the phase results are converted from radians to degrees. The default is TRUE, which means that results are expressed in degrees.
	error in describes error conditions that occur before this node runs. With the following exception, this input provides standard error in functionality. This node runs normally even if an error occurred before this node runs.
	averaging parameters is a cluster that defines how the averaging is computed. The specifications of the parameters include the type of averaging, the type of weighting, and the number of averages. averaging mode specifies the averaging mode. 0 No averaging (default) 1 Vector averaging 2 RMS averaging 3 Peak hold weighting mode specifies the weighting mode for RMS and vector averaging. 0 Linear 1 Exponential (default) number of averages specifies the number of averages used for RMS and vector averaging. If weighting mode is exponential, the averaging process is continuous. If weighting mode is linear, the averaging process stops after this VI computes the selected number of averages.
	restart averaging specifies whether the VI restarts the selected averaging process. If restart averaging is TRUE, the VI restarts the selected averaging process. If restart averaging is FALSE, the VI does not restart the selected averaging process. The default is FALSE. When you call this VI for the first time, the averaging process restarts automatically. A typical case when you should restart averaging is when a major input change occurs in the middle of the averaging process.
	full spectrum returns the forward and reverse discrete order spectra. The full spectrum is the spectrum of the orbit obtained from a sensor pair. forward returns the forward component of the full spectrum. The forward component is the orbit with precession in the same direction as the direction of shaft rotation. reverse returns the reverse component of the full spectrum. The reverse component is the orbit with precession in the opposite direction as the direction of shaft rotation.
	magnitude unit label returns the unit label for the selected magnitude units for the forward and reverse components of full spectrum.
	phase lag returns the phase lag (between probes X and Y) versus order.
	phase unit label returns the unit label for the selected phase units.
	spectrum info returns information about the spectrum needed by the Spectrum Extended Measurements VIs, the Display VIs, and the Tone and Distortion VIs. Note  You must wire spectrum info when performing extended measurements. Do not modify the spectrum info values. If you want to view the information, you can right-click the spectrum info wire and select Custom Probe»Spectrum Info from the shortcut menu.
	error out contains error information. With the following exception, this output provides standard error out functionality. If the value of error in is no error, this VI contains error information that corresponds to the error code input.
	averages completed returns the number of averages completed by the VI at that time.
	averaging done returns TRUE when averages completed is greater than or equal to the number of averages specified in averaging parameters. Otherwise, averaging done returns FALSE. averaging done is always TRUE if the selected averaging mode is No averaging.

OAT Full Spectrum Details

In each instance of OAT Full Spectrum, the reverse component of the full spectrum is returned with negative frequencies for the purposes of easy viewing both the forward and reverse components on the same x axis. The reverse frequencies (or orders) are not actually negative. The full spectrum is typically viewed with forward on the right side of the graph and the reverse displayed on the left side of the graph (with frequencies and orders) reflected across zero. Methods for viewing full spectrum in standard LabVIEW indicators are shown below.

Additional Information

Full Spectrum