Sliding/pop-up roof position measurement, function - GF77.20-P-3001Q

MODEL 209.3 with CODE (414a) Electric glass sliding/pop-up roof 

Direction recognition 

Fig 1: Sliding/Pop-Up Roof Position Measurement Function

Courtesy of MERCEDES-BENZ USA

Position measurement 

The position counter in the overhead control panel control module (N70) counts the Hall pulses from Hall sensor 1 (M12b1) and Hall sensor 2 (M12b2) depending on the recognized direction of rotation of the SR motor (M12m1). The zero position is defined as the position when the pop-up roof is open, i.e. when the pop-up roof is completely opened, the position counter should indicate zero. The zero position is set by the synchronization function. Upon exceeding the zero position in the "Open" direction, the counter status becomes negative.

Direction recognition 

Hall sensor 1 (M12b1) and Hall sensor 2 (M12b2) are located on the shaft of the SR motor (M12m1).These react to the movement of the magnet. They supply one square-wave pulse for each rotation of the motor shaft.

The overhead control panel control module (N70) reads these Hall pulses. The chronological offset of the Hall pulses from Hall sensor 1 (M12b1) and the Hall pulses from Hall sensor 2 (M12b2) allow the overhead control panel control module (N70) to recognize the direction of rotation of the motor.