In a method and a device for transfer of a number of digital data streams accumulating in parallel between units moving relative to one another, the digital data to be transferred are modulated at least partially to avoid excessively high interference radiation. The data are transferred serially between the units (16, 18) and the data are demodulated after the transfer. The data accumulating in parallel and to be transferred are divided up into a number of data sets; the potential or actual tendency for generation of EMI radiation is examined for each data set. A modulation pattern is selected for each data packet dependent on the degree of the tendency to generate EMI radiation, with modulation pattern the EMI radiation arising in the data transfer in connection with the respective data set is largely reduced. Each data set is modulated according to the selected modulation pattern before the transfer.