Method and device for serial data transmission with flexible message size and variable bit length

A method for serial data transmission in a Bussysem having at least two bus stations, which exchange messages via the bus, described, wherein the messages sent have a logical structure according to the CAN standard ISO 11898-1, where (in the presence of a first identification EDL ) the Control field of the messages differing from the cAN standard ISO 11898-1 for more than six bits, and wherein presence of the first marking (EDL), the data field of the message may comprise different from the cAN standard ISO 11898-1 for more than eight bytes wherein for determining the size of the data field, the values ​​of the four bits of the data length codes are at least partially deviating interpreted by the CAN standard ISO 11898-1, and wherein in the presence of a second marking (BRS), the bit length for at least one predetermined or predeterminable range verku a compared with that used before the presence of the second bit length designation within the message assumes physicians value, wherein the region starts at the earliest with the second identification and the latest ending with the CRC delimiter and the second indicia (BRS) only if the first identification (EDL) and occurs in the deviation from the CAN standard ISO 11898-1 comprehensive more than six bits control field of the message takes place.