CAN Bus
Protocal
- SOF = Start of Frame
- Arbitration ID - 11 bit on consumer vehicles, 29 bits on heavy vehicles, also
the priority
- Control Bits
- RTR = Remote Transmission Request, requesting someone to respond
- DLC, IDE… (6 bits in total)
- Data - 64 bits
- CRC = Cyclic Redundancy Checksum, 16 bits, to detect BER (Bit Error Rate) and
self-correct
- ACK: 2 bits
- EOF = End of Frame
- IFS = Inter-Frame Spacing
- Differential signaling, two wires, CAN Low and CAN High, 120 ohm termination
resistor
- ODB-II (on-board diagnostics), which runs as a “higher layer protocol” on CAN
bus