A method and a device for transferring data in a telecommunication system comprising a data transfer path (8) and devices (21, 22, 1) using the data transfer path for data transfer, data being transferred cyclically in messages (4) between the devices according to at least one cycle having a cycle time, whereby the device (1) is configured to monitor the cyclic communication on the data transfer path; determine, on the basis of the monitoring and the cycle time of said at least one cycle of the cyclic communication, at least one expected occurrence time slot of the cyclic communication; and transmit a message not belonging to the cyclic communication to the data transfer path on the basis of at least one determined occurrence time slot such that it does not collide with one or more messages of the cyclic communication occurring in the determined at least one occurrence time slot.