The present invention is a method for identification of manipulations on an arrangement which includes a sensor which emits pulses and a recording unit. As is the case with a tachograph, any possibility of manipulation must be overcome. For this purpose, the sensor transmits real time pulses to the recording unit and, cyclically in response to first request instructions, transmits higher data signals for a measurement, and receives a number of real time pulses in response to second request instructions which are offset in time with respect to the first request instructions. A data signal evaluation module compares the number of real time pulses with the number of data signal pulses and thus achieves a very high level of security against manipulation.