A device and method for a serial bus system. The device has a transmit signal analysis module for counting edges of a transmit signal to be transmitted on a bus of the bus system; a receive signal analysis module for counting edges of a receive signal generated from a signal transmitted on the bus because of the transmit signal; and an evaluation module for evaluating the difference that results from a comparison of the edges counted by the transmit signal analysis module and the edges counted by the receive signal analysis module. If the signal propagation time on the bus is greater than the bit time of the receive signal, the evaluation module signals whether the amount of the difference is less than or equal to a predefined value or whether the amount of the difference is greater than the predefined value, the predefined value being greater than zero.