A sensor element for opening of doors and gates, with the aim being to allow production of a detection field for identification of people andor static objects by means of an antenna element, the antenna element is intended to have a flat antenna unit, with a pin-like antenna projecting at least approximately vertically from the flat antenna unit. The apparatus comprises an attack generator for generating attack traffic on a communications path in the data processing system. The grip comprises a ball support, an arm and means mounting the arm for rotation between a closed position and an open position.