Why Does my Caliper Step Return Wrong Results with the Vision Assistant Express VI? Primary Software: Vision AssistantPrimary Software Version: 7.0 Primary Software Fixed Version: Secondary Software: LabVIEW Development Systems>>Base Package
Problem: I am using the Vision Assistant Express VI in LabVIEW and the Express VI contains a Caliper step that measures the distance between two points on the image. When the Express VI is open, I am able to see these measurements. However, if I configure the VI to output those measurements I only get 0.00 for every measurement. Solution: This is a known issue with Vision Assistant 8.5. However, there is an easy workaround. You can input the indexes of the points that you want to measure as a control. When you have Vision Assistant open, you see a list of all the points that are available for measurement (as shown in figure 1)
Note the list of available points. The order in which these points appear on this list defines the index of each point. Say, in this case that we want to find the distance between the two available points. Their indexes are 0, 1 respectively. When you are at the step for selecting the controls and indicators, be sure to select the Parameters item under the Caliper step (see Figure 2). This creates an input for the parameters on the express VI.
When you click OK, the Express VI should have an input named Parameters on it. You can create a constant from this input and then edit the constant to show the correct indices for the points. Since in this case, we want to find the distance between points 0 and 1, we edit the input constant to match the image in Figure 3.
Now, when you run your code, the correct results will appear in Caliper Results. Related Links: Attachments:
Report Date: 01/21/2008 Last Updated: 01/21/2008 Document ID: 4HKF2D5L |
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