A feature of CAN FD is the ability to have up to 64 bytes in the payload of a frame compared to the only 8 bytes available with classic CAN. This lowers the arbitration overhead to send many frames worth of data. Classic CAN devices are not able to read CAN FD frames and will treat them as an error frame. This means there must be at least one other CAN FD device on the bus to ACK an FD frame. FD also supports [[Bitrate Switching]]. # DLC Field Because the DLC field is only 4 bits in size, above a size of 8 bytes, the value is multiplexed to cover a number of payload sizes up to 64 bytes. | DLC | 9 | 10 | 11 | 12 | 13 | 14 | 15 | | -------- | --- | --- | --- | --- | --- | --- | --- | | **Size** | 12 | 16 | 20 | 24 | 32 | 48 | 64 | # References - [CAN FD - Wikipedia](https://en.wikipedia.org/wiki/CAN_FD)