J1939-Bus

The J1939 bus is a field bus standardized by the Society of Automotive Engineers( SAE) for special heavy-duty transporters, as well as for commercial and special vehicles. J1939 originates from the USA and is based on the physical layer of the CAN bus.

The J1939 bus is used primarily in powertrain and chassis components and is intended to ensure uniformity between the electronic components of different vehicle types and vehicle manufacturers.

The SAE J1939protocol is used for communication between electronic control units and forms the basis for various international standards for trucks, commercial vehicles and trailers, for forestry and agricultural machinery, and for marine applications. The J1939 protocol defines the various data formats and signals. The individual parts of the specification regulate the transmission type for the messages, their content, structure and segmentation.

J1939: General description of the network.

J1939/0X: Description of the application.

J1939/01: Commercial vehicles, truck and bus.

J1939/7X: Application Layer.

J1939/71: Vehicle Application Layer. Vehicle

J1939/73: Application Layer Diagnostics,

J1939/81: Network Management.

J1939/31: Network Layer. Bridge, Router, Gateway, Filter.

J1939/21: Data Link Layer.

J1939/1X: Physical Layer.

J1939/11: Physical Layer, STP cable, 250 kbit/s.

J1939/12: Physical Layer, star quad, 250 kbit/s.

J1939/13: Off- board DiagnosticConnector, diagnostic connector.