Filtec FT-100 Operation Manual page 34

If there is no activity such as operator input or case rejections for
two minutes, a screen saver replaces the MASTER MENU. The
screen saver displays the number of cases inspected. When the
screen saver is active, pressing any key will return you to the
screen displayed before the screen saver was activated.
2-10 FT-100/CI and FT-170/CI Operation Guide
Document 40275-0913