Abstract: A method for data transmission in telegrams in a serial communication protocol comprises the following steps: assigning the user data to be transmitted to telegrams the basic structure of which comprises a telegram header which includes information data about the telegram length, addressing, distribution of the user data to be transmitted into several telegrams or the like; a user data block which includes at least a part of the user data to be transmitted; and a checksum block which includes a checksum that is determined according to a checksum algorithm at least from the user data; and transmission of the telegrams in consecutive intervals along a data transmission path. In this process, the user data block of the telegrams is divided into several user data sub-blocks each of which is protected individually by checksum sub-blocks.