SAE J1939 Protocol Stack

SAE J1939 Protocol Stack Overview

SAE J1939 Protocol Stack

SAE J1939 is used to make sure that all components of a commercial vehicle, such as medium and heavy-duty truck, can communicate each other properly and can be diagnosed systematically. This coding standard is outlined by the Society of Automotive Engineers as a high level communication protocol on a Controller Area Network (CAN). This protocol is needed to accommodate various systems of a vehicle, particularly the fleet management system. This system broadcasts many important data of the vehicle including vehicle speed, cruise control, clutch switch, acceleration, VIN, total engine hours, engineer temperature, and other necessary vehicle information that is needed to be observed when the vehicle is operated when it needs to be diagnosed. SAE J1939 protocol is an enhanced replacement of the previously used SAE J1587/J1708 network protocol.

This protocol defines five of seven OSI layers models. The five OSI model layers that are defined by this protocol are the physical layer model with its bits protocol data unit, the data link layer model with its frames protocol data unit, the network layer model with its packets protocol data unit, the transport layer model with its segments protocol data unit and the application layer model. All of those five OSI layer models are handled by a single software library called the SAE J1939 protocol stack.

This protocol stack is used to translate the received CAN inbound data frames so they can be observed and analyzed by the users. It also provides development of J1939 devices in a quick and simple way. When it is applied, it will transmit and receive specific messages, treats J1939 transport protocols, establish communication with numerous nodes simultaneously, support address claiming process, and transmit and receive messages cyclically with timeout monitoring. The application of this protocol stack enables the developer to develop the application with improved concentration.

SAE J1939 Protocol Stack