# Inspect Parts with Overlapping Acquisition

Use overlapping acquisition on applications such as:

- Continuous welding inspection

- Glue beads

- Extruded parts inspection

- Counting of non-isolated parts on a belt

Using the self-trigger mode allows you to acquire a stream of point clouds without any external trigger needed. In this mode, the vision system acquires point clouds continuously. During the acquisition of a point cloud, the In-Sight 3D Spreadsheet processes the previous point cloud. This parallelization between acquisition and tools processing ensures that there is no gap between the point clouds in the data and in the results.

Additionally, by combining the self-trigger and overlap options, you ensure that a defect or part to inspect is fully acquired in at least one point cloud, especially when working with non-isolated parts in an image. This also allows for higher-resolution inspection.

Note: With overlapping acquisition, the same part or defect can be present in two consecutive point clouds. You need to add logic to ignore it in one of the two point clouds, such as adding a Blob tool. It is possible to perform different inspections on each point cloud, such as Count.

## Set Up Overlapping Acquisition

In this example, the task is to acquire images of donuts moving on a belt. Using the overlap option, each donut is fully acquired in a point cloud.

1. Under Acquisition, go to the Trigger tab.

   Note: Make sure you are Offline.

2. Change the Trigger Type to Self.

3. Set the Motion Input to Encoder or Time, depending on your setup.

4. Go to the Point Cloud tab.

5. Set the Requested Scan Length to the desired size. In this example, the size is 240 cm.

   Note: Configure the Requested Scan Length based on the required resolution multiplied by the maximum allowed number of profiles (8000). You can also use shorter scan lengths to have smaller point clouds and less delayed results.

6. Set the Requested Overlap Length based on the maximum length of the defect or part to inspect. In this example, the size is 60 cm.

   Note: The Requested Overlap Length can be up to 50% of the requested scan length. If you set it beyond the limit, the Requested Scan Length is automatically adjusted. Working with large overlaps is less efficient, as a high percentage of a point cloud is processed twice.

7. Switch Online. The first point cloud is acquired.

8. The second point cloud is acquired with an overlap of the Requested Overlap Length.

   In this example, the second point cloud contains the latest acquired profiles from previous point cloud to ensure that you can inspect the full donut in one of the two point clouds.

9. The vision system continues to acquire point clouds with the overlap.