A method for determining the topology of a serial, asynchronous data bus, to which at least a first bus participant and a second bus participant are connected, who communicate via a predefined bus access protocol, comprising defined request and response telegrams, wherein the method comprises the following steps: transmitting of request telegrams from the first bus participant and receiving the request telegrams at the second bus participant, and transmitting a respective response telegram from the second bus participant in response to each request telegram and receiving the request telegrams at the first bus participant, characterized by: determining a first plurality of time differences between said receiving of a respective request telegram of the first bus participant and said receiving of the respective corresponding response telegram of the second bus participant at a first measurement location at the data bus, determining a second plurality of time differences between said receiving of said respective response telegram of said first bus participant and said receiving of said respective corresponding response telegram of said second bus participant at a second measurement location at the data bus, wherein the first measurement location is located at the first bus participant, or, from the perspective of the second bus participant, is located behind the first bus participant, and the second measurement location is located at the second bus participant, or, from the perspective of the first bus participant, is located behind the second bus participant, calculating a first average response time T res1 for the second bus participant from the determined first plurality of time differences, calculating a second average response time T res2 for the second bus participant from the determined second plurality of time differences, calculating a transmit time delay T L as half of the difference between the first average response time T res1 and the second average response time T res2, whereby a distance between the first bus participant and the second bus participant can be deduced. transmitting of request telegrams from the first bus participant and receiving the request telegrams at the second bus participant, and transmitting a respective response telegram from the second bus participant in response to each request telegram and receiving the request telegrams at the first bus participant, characterized by: determining a first plurality of time differences between said receiving of a respective request telegram of the first bus participant and said receiving of the respective corresponding response telegram of the second bus participant at a first measurement location at the data bus, determining a second plurality of time differences between said receiving of said respective response telegram of said first bus participant and said receiving of said respective corresponding response telegram of said second bus participant at a second measurement location at the data bus, wherein the first measurement location is located at the first bus participant, or, from the perspective of the second bus participant, is located behind the first bus participant, and the second measurement location is located at the second bus participant, or, from the perspective of the first bus participant, is located behind the second bus participant, calculating a first average response time T res1 for the second bus participant from the determined first plurality of time differences, calculating a second average response time T res2 for the second bus participant from the determined second plurality of time differences, calculating a transmit time delay T L as half of the difference between the first average response time T res1 and the second average response time T res2, whereby a distance between the first bus participant and the second bus participant can be deduced. determining a first plurality of time differences between said receiving of a respective request telegram of the first bus participant and said receiving of the respective corresponding response telegram of the second bus participant at a first measurement location at the data bus, determining a second plurality of time differences between said receiving of said respective response telegram of said first bus participant and said receiving of said respective corresponding response telegram of said second bus participant at a second measurement location at the data bus, wherein the first measurement location is located at the first bus participant, or, from the perspective of the second bus participant, is located behind the first bus participant, and the second measurement location is located at the second bus participant, or, from the perspective of the first bus participant, is located behind the second bus participant, calculating a first average response time T res1 for the second bus participant from the determined first plurality of time differences, calculating a second average response time T res2 for the second bus participant from the determined second plurality of time differences, calculating a transmit time delay T L as half of the difference between the first average response time T res1 and the second average response time T res2, whereby a distance between the first bus participant and the second bus participant can be deduced.