J1939

Quick Summary:

J1939 is the automotive CAN standard developed by the Truck & Bus Control and Communications Network Subcommittee of the Society of Automotive Engineers. SAE maintains family of standards which govern the design and use of devices that transmit electronic signals and control information among vehicle components. Planned for use in light, medium and heavy-duty trucks, it is also now being used in conventional passenger vehicles.

NetBurner J1939 Product Summary:

All NetBurner products that have a CAN port and support the standard NetBurner development software support CANopen. Contact Real Time Automation for J1939 Embedded Gateway and Master and Slave Source File solutions.

Overview:

J1939 was designed for the CAN 2.0 (CAN Part B) specification. It is unique in that it is the only application layer in this paper that uses the larger 29 bit identifier and the only one that does not require a master. Instead of the traditional Master-Slave relationship, it uses a peer to peer protocol where most messages are broadcasted versus directed to individual nodes.

In J1939 each CAN Node is referred to as an Electronic Control Unit (ECU). Every ECU has at least one node address. In certain applications ECUs have multiple node addresses in the same electronic assembly.

J1939 uses three methods to communicate over the CAN bus. Destination specific communications use the PDU1 (Protocol Data Unit 1) format to send and receive data. The PDU1 format allows a message to be directed to specific ECU (CAN Node). The destination address is included in the CAN PDU1 CAN frame. Broadcast Communications use the PDU2 (Process Data Unit 2) format to send a message to multiple nodes. The PDU2 message format identifies a message number versus a node number. In these applications receiving ECU’s monitor the CAN bus for specific messages. For example a display unit may ignore all other messages as it monitors the bus waiting for the PDUs containing Fuel Temperature and Fuel Pressure.

Proprietary Communications use both PDU1 and PDU2 formats to send data. This is commonly used in service tools.

Data transferred on the CAN bus is defined as Parameter Groups (PGs). PG’s define where the data is located in the CAN Data frame, priority and transmission repetition rate. PG’s are identified with Parameter Group Numbers (PGN’s) and are similar to EDS (Electronic Data Sheets) used in DeviceNet.

Ethernet/IP Server C Source Code

The easiest way to add support EtherNet/IP on all your NetBurner Coldfire products!
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