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Amplitude and Levels VI

LabVIEW 2010 Help

Edition Date: June 2010

Part Number: 371361G-01

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Owning Palette: Waveform Measurements VIs

Requires: Full Development System

Returns the amplitude, high state level, and low state level of a waveform or an array of waveforms. Wire data to the signal in input to determine the polymorphic instance to use or manually select the instance.

Details  Example

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

Amplitude and Levels 1 chan

signal in is the waveform to measure.
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
state settings specifies the method used to determine the high and low state levels of a waveform. For pulse and transition waveform measurements, state levels provide a means to identify the position in time of the waveform feature to be measured.
method specifies how LabVIEW computes the high and low state levels of the waveform.

0Histogram—Returns the levels of the histogram bins with the maximum number of hits in the upper and lower regions of the waveform. The upper and lower regions of the waveform include the upper and lower 40%, respectively, of the peak-to-peak range of the waveform.
1Peak—Searches the entire waveform for its maximum and minimum levels.
2Auto select (default)—Determines whether the histogram bins that correspond to the high and low state levels each have over 5% of the total hits. If so, LabVIEW returns those results. Otherwise, LabVIEW uses the peak method. This ensures a reasonable answer for either a square wave (ignoring the overshoot and undershoot) or a triangle wave (where a histogram fails).
histogram size specifies the number of bins in the histogram LabVIEW uses to determine the high and low state levels of the waveform. If you select the peak method, LabVIEW ignores this input.
histogram method specifies how LabVIEW computes the high and low state levels of the waveform. Currently, mode is the only available histogram method.

0Mode
reserved is reserved for future use.
amplitude is the difference between high state level and low state level.
high state level specifies the level at which a pulse or transition waveform is defined to be in its highest state.
low state level specifies the level at which a pulse or transition waveform is defined to be in its lowest state
error out contains error information. This output provides standard error out functionality.

Amplitude and Levels N chan

signal(s) in is an array of waveforms containing the signals to measure.
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
state settings specifies the method used to determine the high and low state levels of a waveform. For pulse and transition waveform measurements, state levels provide a means to identify the position in time of the waveform feature to be measured.
method specifies how LabVIEW computes the high and low state levels of the waveform.

0Histogram—Returns the levels of the histogram bins with the maximum number of hits in the upper and lower regions of the waveform. The upper and lower regions of the waveform include the upper and lower 40%, respectively, of the peak-to-peak range of the waveform.
1Peak—Searches the entire waveform for its maximum and minimum levels.
2Auto select (default)—Determines whether the histogram bins that correspond to the high and low state levels each have over 5% of the total hits. If so, LabVIEW returns those results. Otherwise, LabVIEW uses the peak method. This ensures a reasonable answer for either a square wave (ignoring the overshoot and undershoot) or a triangle wave (where a histogram fails).
histogram size specifies the number of bins in the histogram LabVIEW uses to determine the high and low state levels of the waveform. If you select the peak method, LabVIEW ignores this input.
histogram method specifies how LabVIEW computes the high and low state levels of the waveform. Currently, mode is the only available histogram method.

0Mode
reserved is reserved for future use.
amplitude is an array containing the amplitude of each waveform in signal(s) in.
high state level is an array containing the high state level of each waveform in signal(s) in.
low state level is an array containing the low state level of each waveform in signal(s) in.
error out contains error information. This output provides standard error out functionality.

Amplitude and Levels Details

The terminology and measurement definitions for this VI comply with IEEE Standard 181-2003, IEEE Standard on Transitions, Pulses, and Related Waveforms.

Example

Refer to the N chan Pulse and Transition Measurements VI in the labview\examples\measure\maxmpl.llb for an example of using the Amplitude and Levels VI.


 

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