Physical layer

CAN was one of the first protocols to be extremely robust and reliable in the world of Industrial Automation. It was the first protocol to employ a distributed coordination on a bus with extremely high levels of fault tolerance and error handling. What makes it special is the technology behind the transmissions on the bus.

The physical layer must be described in all its main different parts:

1. Collision handling
2. Bus characterization
3. Encoding and synchronization

Few notes on standardization

CAN has been standardized into ISO 11898.

• Section ISO 11898-1 of the document covers the features of the physical layer.
• Sections ISO 11898-2 and ISO 11898-3 cover the specifications of transceivers for high and low speed communications.
• Other sections of the standard cover connectors.