Patent ID: 9600425
Date: 2017-03-21
CPC Classifications: G06F,H03M,H04L

Claim:
1. A method for serial data transmission in a bus system having at least two subscribed data processing units, the method comprising: exchanging messages via the bus; providing that the transmitted messages have a logical structure according to CAN standard ISO 11898-1, the logical structure including a start-of-frame bit, an arbitration field, a control field, a data field, a CRC field, an acknowledge field and an end-of-frame sequence; providing that the control field includes a data length code, which contains information about the length of the data field; wherein the data field of each of the messages is selectably variable to include a variable maximum number of bytes selected from eight bytes to more than eight bytes in deviation from the CAN standard ISO 11898-1, the values of the data length code being interpreted as least partially in deviation from the CAN standard ISO 11898-1 for determining the size of the data field of each respective message, and wherein the CRC field of transmitted messages has at least two different numbers of bits depending on the content of the data length code, the CRC field having a greater number of bits for a data length code indicating a longer data field than for a data length code indicating a shorter data field, wherein if the maximum number of bytes of the data field is eight bytes, the CRC field of transmitted messages has a predetermined number of bits independent of a content of the data length code, and wherein if the maximum number of bytes of the data field is more than eight bytes, the CRC field of transmitted messages has a number of bits depending on the content of the data length code.