According to one embodiment, a semiconductor manufacturing apparatus comprises an electrostatic chuck and a control unit. The filtering device includes a plurality of linear filters corresponding to medians and diagonals considered on the sensor for supplying a plurality of filtering indications. The windings of each group are controlled by a control circuit individually assigned to it. Based on a time-variable signal which is accessible to both system components, at the start of the vehicle, one of the test codes is selected by both system components via an assignment function present as a hash function, and with this test code, the payload data that are to be transmitted are coded.