## Appendix A: Troubleshooting PC-DMIS Vision

Use this troubleshooting guide to find solutions to your PC-DMIS Vision problems.

Problem: No image in Live View

- Ensure the Frame Grabber drivers have been installed.

Problem: DCC machine does not move

- Check the Max Speed setting in the Motion tab of the Machine Interface Setup dialog box.

Problem: Point Detection takes a long time

When using Matching Edge selection type for an Automatic Hit Target, image detection can sometimes take a long time. Try the following to speed up the detection:

- Reduce scan tolerance (width of the target band). With a narrower band, PC-DMIS Vision has fewer "edges" it has to evaluate in order to find the correct one.

- Change the illumination. You may have a lot of surface texture which can give the Matching Edge algorithm more to do. Make the feature a back light measured one (as you'd normally do on holes). Switch off the top light, and switch on the back light.

- Use the Clean Filter from the Filter Parameter Set to remove small dirt and weak edges from the image.

- If the previous steps don’t help, use one of the other edge detection methods. Matching Edge is the most reliable for finding the correct edge, but it is the most processor intensive. On this particular edge, try Specified Edge, with the direction going from inner to outer.

Problem: Point Detection finds false edge points on parts with strong surface texture

- Use the Clean Filter from the Filter Parameter Set to remove small dirt and weak edges from the image.

- Where possible, use bottom light sources with no top light.

Problem: Point Detection finds false edge points on parts with gentle gradient/shadow

- Switch off the Clean Filter from the Filter Parameter Set.

Problem: Poor Focus accuracy

- Focus operations (manual and automatic) should always be done at highest possible magnification.

- Use AUTO control mode where possible. If using FULL control, a slower speed allows for more data collection, improving the accuracy.

- Set the illumination to provide as much contrast as possible on the surface/edge.

Problem: Poor Manual Focus repeatability

- When moving the stage, aim for a slow and steady speed.

- You can move forwards and backwards over the focus point (to get multiple peaks on your graph) if the focus time allows it. See the "Focus Graph" topic.