Caliper Controls

NI Vision Builder

Measure Features Tab

Caliper Controls

Main Tab

The following controls are available on the Main tab.

Control Name Description
Step Name Name to give the step.
Region of Interest The region of interest you want to use for the step.
Reposition Region of Interest When enabled, the step dynamically repositions the region of interest based on a coordinate system you built in a previous step.
Reference Coordinate System Coordinate system to which you want to link the region of interest.

Settings Tab

The following controls are available on the Setting tab.

Control Name Description
Process Type of caliper to use. The following options are available:
  •   Horizontal Max Caliper—Measures a distance in the horizontal direction from the vertical sides of the region of interest toward the center of the region of interest.
  •   Horizontal Min Caliper—Measures a distance in the horizontal direction from the center of the region of interest toward the vertical sides of the region of interest.
  •   Vertical Max Caliper—Measures a distance in the vertical direction from the horizontal sides of the region of interest toward the center of the region of interest.
  •   Vertical Min Caliper—Measures a distance in the vertical direction from the center of the region of interest toward the horizontal sides of the region of interest.
Gap Number of pixels between search lines in the region of interest.
Edge Strength Minimum difference in the intensity values between the edge and its surroundings. Only those edges whose strength is greater than this value are used in the detection process.
Smoothing Number of pixels averaged to find the contrast at either side of the edge.
Steepness Maximum distance in which the edge strength must occur. Steepness characterizes the slope of the edge. Use a higher Steepness value to detect edges in images whose pixel intensities gradually transition from the background to the edge.
Edge Strength Profile Edge strength along the search line located in the middle of the region of interest.

Limits Tab

The following controls are available on the Limits tab.

Note  When you calibrate the image using a Calibrate Image step, all distances are returned using the specified calibration units.
Control Name Description
Minimum Distance When enabled, the minimum distance you expect the step to measure between the caliper arms in order for the step to pass.
Maximum Distance When enabled, the maximum distance you expect the step to measure between the caliper arms in order for the step to pass.
Current Distance Distance measured between the caliper arms.