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J1939 Transmit

Transmit J1939 message

  • J1939 Transmit block

Simulink Real-Time / J1939 Communication
Vehicle Network Toolbox / J1939 Communication


The J1939 Transmit block transmits a J1939 message. The J1939 database file defines the nodes and parameter groups. You specify the J1939 database by using the J1939 Network Configuration block.

To use this block, you must have a license for both Vehicle Network Toolbox™ and Simulink® software.

The J1939 communication blocks support the use of Simulink accelerator and rapid accelerator modes. You can speed up the execution of your models by using these modes. For more information, see Acceleration.

The J1939 communication blocks also support code generation that have limited deployment capabilities. Code generation requires a C++ compiler that is compatible with the code generation target. For the current list of supported compilers, see Supported and Compatible Compilers.



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Depending on the J1939 parameter group and signals defined in the J1939 database file, the block can have multiple data input ports.

Enables the transmission of the message for that sample. A value of 1 specifies to send, a value of 0 specifies not to send.


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The name of the J1939 network configuration to associate with. This is used to access the corresponding J1939 database. Only the nodes defined in the model and associated with the specified J1939 network configuration appear in the Node name list. The option shows none if no J1939 network configuration is found.

The name of the J1939 node. The drop-down list includes all the nodes in the model, both custom nodes and nodes from the database.

The parameter group number (PGN) and name from the database. The contents of this list vary depending on the parameter groups that the J1939 database file specifies. The default is the first parameter group for the selected node.

If you change any parameter group settings within your J1939 database file, you must then open the J1939 Transmit block dialog box and select the same Parameter Group, then click OK or Apply to update the parameter group information in the block.

Signals defined in the parameter group. The Min and Max settings are read from the database, but by default the block does not clip signal values that exceed this range.

Priority of the parameter group, read from the database. This priority setting resolves clashes of multiple parameter groups transmitting on the same bus at the same time. If a conflict occurs, the priority group with lower priority (higher value) will refrain from transmitting. The value can range from 0 (highest priority) to 7 (lowest).

The name of the destination node. The default is the first node defined in the database, otherwise Custom.

For a custom destination address, you can specify 0–253 for the address of the destination node. For broadcasting to all nodes, use the Custom Destination Address setting with an address of 255.

The simulation transmit rate, specified as the sampling time of the block during simulation. This value defines the frequency at which the J1939 Transmit block transmits messages. The default value of -1 is used when the block is inside a triggered subsystem or inherits a sample time. You can also specify a MATLAB® variable for sample time. For information about simulation sample timing, see What Is Sample Time?.

Version History

Introduced in R2015b