Confirming this symbol calls up the calibration screen.
The following image will appear:
Tap the touch pen on the centre of each cross as it appears.
After each touch, the cross will move to the next calibration point.
The crosses will appear in the following sequence:
If the calibration point was set incorrectly, the calibration must be repeated.
Once you have tapped on the last cross, the calibration has been completed and the confirmation screen will pop up.
If you have hit the centre of the crosses with sufficient precision, press "Confirm".
If the calibration was not precise enough, the button cannot be pressed.
In this case, or if you want to repeat the calibration for another reason, wait for a few seconds for the calibration screen to pop up again.
If an external keyboard is connected to the operator interface, the calibration process can be cancelled at any time by pressing <ESC>.