Digital Compare Express VI

LabView Acquire Signals Express VIs

Digital Compare Express VI

Owning Palette: Test and Compare Express VIs

Installed With: LabVIEW SignalExpress

Compares a reference and test signal to determine the number of sample errors.

Dialog Box Options
Block Diagram Inputs
Block Diagram Outputs
 Place on the block diagram  Find on the Functions palette

Dialog Box Options

ParameterDescription
Digital waveform previewDisplays the two waveforms to be compared.
Signal name previewDisplays the signal names associated with the signals in the Digital waveform preview.
Digital preview Y scrollbarScrollbar that allows you to scroll through the Digital waveform preview.
InputContains the following options:
  • Reference waveform—Displays the signal that will serve as the reference for your comparison. Sample errors are produced when the test waveform differs from this waveform.
  • Test waveform—Displays the signal you want to compare to the reference signal. Sample errors are produced when the test waveform differs from the reference waveform.
ConfigurationContains the following options:
  • Comparison Start Position—Contains the following options:
    • Reference waveform start—Specifies the position of the sample where you want to start the signal comparison.
    • Test waveform start—Specifies the position of the sample where you want to start the signal comparison.
  • Compare subset—Specifies whether you want to compare the entire test signal to the reference signal or whether you only want to compare a subset of the samples. Selecting this checkbox means that a subset that is the number of samples specified in Number Samples will be compared, starting at the reference waveform start position you specify.
  • Number of samples—Specifies the number of samples in the subset the VI compares.
  • Passed—Displays the result of the waveform compare. If all specified samples match, the compare passes. Otherwise, the compare fails, and the number of sample errors is returned in Number of Sample Errors.
  • Number of Sample Errors—Returns the number of sample errors in the test signal.

Block Diagram Inputs

ParameterDescription
error in (no error)Describes error conditions that occur before this VI or function runs.

Block Diagram Outputs

ParameterDescription
error outContains 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.