The collision detection happens by monitoring the transmitted and actual bits on the bus. A bit-wise arbitration on the arbitration field bits is used to resolve who continues and who waits. By the end of the arbitration field only one node is left with the right to use the bus.
Data frame
| SOF | arbitration | control | data | checksum | ack | EOF |
| 1 bit | 11 bits | 0-8 bytes | 16 bits | 1 bit | 7 bits | |
| synchronous signalling | allows for priority resolution | includes length of data field | message objects may be up to 8 bytes long | why so long? |