Abstract: In a method for detecting a varying data rate in a data signal, with which data signal a bit is transmitted in the form of a signal edge generated at a particular nominal time, after triggering by an interrupt signal (IS) generated in an analog/digital converter (13), the times of occurrence (TA, TB, TC, TD) of the signal edges are detected and subsequently the edge intervals (T1, T2) determined from the times of occurrence (TA, TB, TC, TD) of the signal edges and subsequently the mean edge interval (Tm) determined from the determined edge intervals (T1, T2). From the mean edge interval (Tm) and a tolerance range of the mean edge interval (Tm) are determined an upper time of occurrence limit (OAZ) and a lower time of occurrence limit (UAZ), within which upper and lower time of occurrence limit a subsequent signal edge must occur in order to be valid for the detection of a current data rate from the mean edge interval (Tm).