A method and device for driving a digital speaker based on code conversion are provided in the invention. This simplified abstract is not intended to limit, and should not be interpreted as limiting, the scope of the claims. A pulsed alarm signal having a fixed number of pulses is generated at each remaining device in response to the rising edge. In some embodiments, the interface has a feature with curved portions. A device for measuring the centricity of a conductor in an insulating casing includes an inductive measuring apparatus, first and second optical measuring apparatus and an evaluation apparatus.