A method and a device for exchanging data in messages between at least two stations connected by a bus system. The messages contain the data being transmitted by the stations over the bus system. Each message contains an identifier characterizing the data contained therein. Each station decides on the basis of the identifier whether to receive the message. The messages are controlled in time by a first station. The first station repeatedly transmits a reference message over the bus in at least one specifiable time interval. The time interval is subdivided into time windows of a specifiable length, the messages being transmitted in the time windows.