[Cause]
The 4 large dots could not be correctly identified during measurement of the dot-grid plate fixture.
[Countermeasure]
Check whether the calibration plate is tilted too much. Also take the following countermeasures so that the large dots can be detected correctly.
・ Clean the calibration plate if it is dirty.
・ Use another calibration plate if the calibration plate has large scratches.
・ Adjust the search range to a size that surrounds the calibration plate.
・ If the background is visible around the calibration plate, hide it with cardboard.
This alarm also occurs if the pattern is created in reverse. Check whether the pattern you created is reversed.