[Cause]
Automatic calculation of the focal length failed during measurement of the dot-grid plate. The focal length cannot be determined correctly when the camera directly faces the dot-grid plate fixture.
[Countermeasure]
Study any of the following responses:
・ If the camera is mounted on the robot or the dot-grid plate fixture is mounted on the robot hand, it is recommended to change the number of “calibration planes” to “2” and perform calibration. Otherwise, set “Focal length” to “Next value”, enter the nominal focal length of the lens, and perform calibration.
・ When using a lens with an orthographic projection method, such as a telecentric lens, change “Projection method” to “Orthographic projection” and then perform calibration. If the condition does not improve after the above countermeasures, record the conditions of occurrence and operating steps, execute the abnormal-condition recording function, obtain an image backup, and contact FANUC.