EXFO FTB-500 - Manual (Page 80)

Setting Up Your FTB-500
72 FTB-500
Recalibrating the Touchscreen
5. Using the stylus (or any blunt pointing device), simply press the center
of the different targets that appear on the screen. Keep pressing until
the application displays Lift off to proceed to indicate that the new
parameters have been taken into account.
Note: If you want to stop the calibration process, stop pressing the screen. The
application will close automatically after a few seconds and you will return
to the touchscreen calibration tool window.
When the number of calibration points is reached, the application will
display a message indicating that the calibration is in progress.
6. When the application prompts you, press the center of a last target to
complete the calibration operation. Once it is done, you return to the
touchscreen calibration tool window automatically.
7. Tap OK to close the window. Tap OK again to return to the System
Settings window.
Operation is underway
New parameters taken into account