A method for processing data of a control unit in a data communication device, which has a first memory area and a second memory area, and is connected to the control unit through an interface. Data from the control unit is transmitted to the data communication device through the interface. A value is stored identically in the first memory area and in the second memory area. The data communication device tests whether a first trigger is present, and if present, storage in the first memory area is discontinued, or the trigger class of the first trigger is tested and storage in the first memory area is discontinued only in the presence of a predefined trigger class. Subsequently, values of the data are read out from the first memory area, whereby values arriving chronologically after the first trigger are stored in the second memory area by the data communication device.