Device for transmitting data between two physical interfaces, with - two physical interfaces (1, 2), of which a first physical interface is mounted on a rotating unit, and a second physical interface is mounted on a stationary unit, - a data transmission unit in the form of a circular ring which is arranged between the physical interfaces (1, 2) and transmits the digital data along a data transmission channel, and - one local oscillator unit assigned to each of the physical interfaces for stamping a local system time in force at the location of one of said physical interfaces, wherein the local oscillator unit at least at one of the physical interfaces includes a means for generating and transmitting at least one clock signal to the data transmission unit, and the local oscillator unit at least at the other physical interface includes a means for receiving the at least one clock signal that is transmitted via the data transmission unit along exactly the same transmission channel as the digital data are also transmittable as well as a means for synchronising the local system times on the basis of the received clock signal, characterized in that a buffer in the form of a ring buffer is provided at each physical interface receiving the digital data, the memory depth of which is selected according to a temporal phase shift formed in the transmitted digital data in the course of the data transmission, and in which the digital data transmitted by means of the data transmission unit can be buffered temporarily, that a means is provided which detects the phase shift formed in the course of the data transmission, and that a further means is provided which defines the memory depth depending on the phase shift. - two physical interfaces (1, 2), of which a first physical interface is mounted on a rotating unit, and a second physical interface is mounted on a stationary unit, - a data transmission unit in the form of a circular ring which is arranged between the physical interfaces (1, 2) and transmits the digital data along a data transmission channel, and - one local oscillator unit assigned to each of the physical interfaces for stamping a local system time in force at the location of one of said physical interfaces, wherein the local oscillator unit at least at one of the physical interfaces includes a means for generating and transmitting at least one clock signal to the data transmission unit, and the local oscillator unit at least at the other physical interface includes a means for receiving the at least one clock signal that is transmitted via the data transmission unit along exactly the same transmission channel as the digital data are also transmittable as well as a means for synchronising the local system times on the basis of the received clock signal, characterized in that a buffer in the form of a ring buffer is provided at each physical interface receiving the digital data, the memory depth of which is selected according to a temporal phase shift formed in the transmitted digital data in the course of the data transmission, and in which the digital data transmitted by means of the data transmission unit can be buffered temporarily, that a means is provided which detects the phase shift formed in the course of the data transmission, and that a further means is provided which defines the memory depth depending on the phase shift.