Abstract: The invention relates to a device for checking the angular position and the starting position of a roller supporting a plurality of indicating pallets, which roller is driven in stepwise rotation. The device comprises magnetic members adapted to sense the position of magnetic poles provided on the roller or on a member mechanically linked to the roller, whereby the number of steps taken by the roller, starting from a predetermined position, can be counted taking advantage of a circumferentially arranged Hall effect and without contact between the sensing members and the roller or the member mechanically linked thereto.