Roland VersaCamm VS-640 Service Notes page 263

HEAD UP/DOWN SENSOR
It detects the position of the Head Height Lever.
THERMISTOR
It takes the temperature around the Head.
WIPER SENSOR
It detects the limit position of the Wiper
movement.
ENCODER MODULE
It detects the coordinates in the carriage moving
direction, and also generates the print signal.
5-3