Current Help System: PC-DMIS Laser (View Core Help)

#### To Create a Perimeter Scan

To create a Perimeter scan:

1. Ensure that you have a Laser probe enabled.

2. Place PC-DMIS into DCC mode.

3. Select the
   Insert | Scan | Perimeter menu item. The Scan dialog box appears with Perimeter Scan already selected from the Scan Type list.

4. Select the surface(s) that will be used to create the boundary. If multiple surfaces are selected, the surfaces should be selected in the same order that they are to be traversed by the scan. To select the necessary surface(s):

5. Verify that the Select check box is selected. Each surface will be highlighted as it is selected.

6. After the desired surfaces are selected, clear the Select check box.

7. Click on the surface near the boundary where the scan is to begin. This is the Start Point.

8. Click on the same surface a second time in the direction that the scan will be executed. This is the Direction Point.

9. Click on the point where the scan is to end. This point is optional. If an End Point is not provided, the scan will end at its Start point.

10. Type the appropriate values into the Scan Construction area. These include the following boxes:

- Increment box

- CAD Tol box

- Offset box

- Offset Tol (+/-) box

11. Select the Calculate Boundary button. This will calculate the boundary from which the scan will be created. The red dots on the boundary indicate where the hits are taken on the perimeter scan.

The boundary calculation should be a relatively quick process.
If the boundary does not look correct, click the Delete button. This will delete the boundary and allow another to be created.
If the boundary appears incorrect, it usually means that the CAD tolerance needs to be increased.
After changing the CAD tolerance, click the Calculate Boundary button to recalculate the boundary.
Verify that the boundary is correct before calculating a perimeter scan because it takes much longer to calculate the scan path than it does to recalculate the boundary.

12. Verify that the Offset value is correct.

13. Click the Generate button. PC-DMIS will then calculate the theoretical values that will be used to execute the scan. This process involves a very time intensive algorithm. Depending on the complexity of the selected surfaces and the amount of points that are being calculated, it may take a while to compute the scan path. (A five minute wait is not uncommon.) If the scan does not appear correct, the Undo button can be used to delete the proposed scan path. If needed, the Offset Tolerance can be altered and the scan recalculated.

14. If needed, you can delete individual points by selecting them one at a time from the Theoretical Path area and pressing the DELETE key.

15. Enter the ID of the cloud of points object that will receive the surface data in the Point Cloud Reference Feature edit box.

16. Click the Create button to store the perimeter scan in the Edit window. It will be executed like any other scan. If you have PC-DMIS's AutoWrist method enabled but don't have any calibrated tips, PC-DMIS will display a message informing you when it adds new probe tips that need calibration. In all other cases PC-DMIS will ask you whether it should use the closest calibrated tip to the needed tip angle or add in a new non-calibrated tip at the needed angle.

Three surfaces have been selected. Each surface borders another, but the outside of each surface makes up the composite boundary (indicated by the solid red line) The offset distance is the amount that the scan will be offset from the composite boundary (indicated by the dotted red line)

Perimeter Scan Example