Patent ID: 7898987

Claim:
A method for an exchange of data in messages between at least two users connected by a bus system, each one of the at least two users including at least one of a predefinable timing mark and an ascertainable timing mark, the method comprising: causing the at least two users to transmit via the bus system messages including the data; causing a first one of the at least two users, in a function as timer, to control the messages as a function of time such that the first one of the at least two users repeatedly transmits a first reference message including a first time information regarding a time base of the first one of the at least two users, via the bus system at a specifiable time interval; and if the at least one of the predefinable timing mark and the ascertainable timing mark of a second one of the at least two users is reached without the first reference message of the first one of the at least two users reaching the second one of the at least two users, causing the second one of the at least two users to take over the function of timer by transmitting a second reference message with a second time information regarding a time base of the second one of the at least two users, via the bus system, wherein one of the first time information and the second time information is used by a receiving user to calculate a global time as a function of a local time information and the one of the first time information and the second time information.