CAN application layer (CAL)

The CAN Application Layer (CAL) forms the application layer in the protocol hierarchy of the CAN bus.

The CAL layer is directly based on the link layer and includes the specification of CAN messages, network management, identifier distribution and layer management. The CAL layer was specified by CAN-in-Automation (CiA) and published in 1993 and provides an application-independent, object-oriented environment for the implementation of distributed CAN-based systems. It is extremely flexible, supports objects and services, but does not define standardized data contents like CANopen or DeviceNet.