In the data exchange method in a multiprocessor system which has a primary processor and at least one secondary processor which communicate with one another via a system bus, with data being able to be exchanged with an application system via an interface to the primary processor, recurrent standard messages contain application data, so that, first, it is possible for application data to be prescribed during the application of the multiprocessor system, and, second, an application data item used as a polling system can be used to display values of memory cells in the secondary processors on the application system without the user on the application system needing to have any knowledge of the internal structure of the multiprocessor system.