US Patent 7500151 Data logging in a motor vehicle

The invention relates to a method for logging messages on a data bus and temporarily storing the sent messages in a cyclically overwritable volatile storing means. The temporarily stored messages can be examined in a targeted manner for attributes of interest by using a verification program. A storage of the temporarily stored messages in a non-volatile second storing means can be initiated by means of definable trigger events that, for example, are formed from individual or a number of attributes of the messages. To this end, the occurrence of the defined trigger event is determined by a monitoring unit, and the data content of the volatile storing means are subsequently transferred into the storage locations of the non-volatile storing means.