#iso11898

Controller Area Network (CAN Bus) - Physical Layer And Bus Topology

The ISO/OSI Reference Model specifies seven levels starting with the physical connection up to the actual user application, i.e., the Application Layer.

The standard CAN Bus implementation neglects the connection between the Data Link Layer and the Application Layer to save on relevant memory resources by reducing the overhead and, as a result, increasing performance as required for embedded solutions with restricted resources.

After all, all layers above the Data Link Layer require supplementary software resources (higher layer protocols).

Galvanically Isolated CAN Bus Transceivers Protect Networks Against Destructive Energy

High noise levels on a CAN bus network have the potential to destroy CAN bus transceivers. This noise originates mainly from two sources, ground loops and electrical line surges.

Protecting a network against this destructive energy requires the galvanic isolation of the CAN bus system from other local node circuitry.