Printronix L5035 Maintenance Manual page 298

Appendix D
Optional Power Paper Stacker
Paper Surface Sensor 1 (PSS1),
Paper Surface Sensor 2 (PSS2)
The paper surface sensor 1 and paper surface sensor 2 are each composed
of light emitters and receptors located on the front side and rear side. When
paper stacking on the elevator table reaches the height of the sensors, the
light is blocked, turning on the sensors. These sensors control the height of
the elevator table. When both sensors come on for 1.5 seconds, the paper
surface is judged to have reached this height, and the elevator table drops 5
to 7 mm.
676