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force and exponential window settings specifies the parameters for the force and exponential windows. These windows are specified in percentages and are used to analyze transients.
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force window [%] specifies the length of the force window that is used if window is set to Force-Exponential. The default is 50.00%. force window [%] specifies the duration of the force window as a percentage of the total duration of the signal. Setting force window % at 100 has the effect of not applying any window on the stimulus signal.
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exp window [%] specifies the decay rate of the exponential window that is used if window is set to Force-Exponential. The default is 10.00%. exp window [%] specifies the remaining level of the applied exponential window at the end of the signal as a percentage.
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scaled signal X [EUx] specifies the scaled signal expressed in the selected engineering units. scaled signal X [EUx] is generally the stimulus or excitation signal in dual-channel measurements.
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t0 specifies the start time of the waveform.
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dt specifies the time interval in seconds between data points in the waveform.
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Y specifies the data values of the waveform.
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scaled signal Y [EUy] specifies the scaled signal expressed in the selected engineering units. scaled signal Y [EUy] is generally the response signal in dual-channel measurements.
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t0 specifies the start time of the waveform.
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dt specifies the time interval in seconds between data points in the waveform.
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Y specifies the data values of the waveform.
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window specifies the time-domain window to use. The default is Hanning.  | Note When you use a Force-Exponential window, wire force/exp settings. |
| 0 | None | | 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 | | 10 | Force-Exponential | | 11 | Blackman Nuttall | | 30 | Triangle | | 31 | Bartlett-Hanning | | 32 | Bohman | | 33 | Parzen | | 34 | Welch | | 60 | Kaiser | | 61 | Dolph-Chebyshev | | 62 | Gaussian |
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frequency range specifies the frequency band of analysis. The valid range for the start frequency and for the stop frequency is between 0 and the Nyquist frequency.
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start frequency specifies the lowest frequency of interest for the analysis band in hertz. The valid range is between 0 and the Nyquist frequency. The default is 1,000.00 Hz.
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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. The default is 5,000.00 Hz.
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dB On specifies if results are expressed in decibels. The default is TRUE. The dB reference is specified when the scaling from voltage to engineering units is applied. You can use the SVFA Unit Conversion VI to change the dB reference for spectra.
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error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
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averaging parameters specifies how the averaging is computed. The specifications of the parameters include the type of averaging, the type of weighting, and the number of averages. | Note When averaging mode is set to No averaging, the VI ignores the weighting mode, number of averages, and linear mode settings. |
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averaging mode specifies the averaging mode.
| 0 | No averaging (default) | | 1 | Vector averaging | | 2 | RMS averaging |
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weighting mode specifies the weighting mode. The default is exponential. | Note RMS and vector averaging support linear and exponential weighting. |
| 0 | Linear | | 1 | Exponential (default) |
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number of averages specifies the number of averages used by the selected weighting mode. The default is 10. If weighting mode is set to Linear, the measurement stops or automatically restarts after the value of number of averages has been reached. Whether the measurement stops or automatically restarts depends on the linear mode setting.
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linear mode specifies the behavior of the averaging if you set the value of the weighting mode parameter to Linear. If you set weighting mode to Exponential, linear mode is ignored.
| 0 | One shot (default)—Specifies that the averaging process stops once the value of number of averages is reached. | | 1 | Auto restart—Specifies that the averaging process automatically restarts after the value of number of averages is reached. |
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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.
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coherence returns information about the coherence.
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f0 returns the start frequency of the coherence expressed in hertz.
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df returns the frequency resolution of the coherence expressed in hertz.
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coherence returns the coherence.
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coherent output power [dB EUy] returns the coherent output power spectrum. This spectrum provides the measurement of what part of the power spectrum is fully coherent with the input signal.
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f0 returns the start frequency, in hertz, of the spectrum.
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df returns the frequency resolution, in hertz, of the spectrum.
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magnitude is the magnitude of the coherent output power spectrum.
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unit label returns the selected engineering units.
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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. |
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error out contains error information. This output provides standard error out functionality.
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averages completed returns the number of averages completed by the VI at that time.
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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.
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