J1939 Message Trigger

J1939 Message Triggering


Simulink® Real-Time™ Library for J1939


The J1939 Message Trigger block triggers the transmission of a J1939 message under conditions that the block specifies. When using this block in your model, connect its Trigger Out port to the Trigger input port of the J1939 Transmit Message block. The possible triggering conditions are:

  • Nonzero input at the Trigger Message input port

  • Expiration of the repetition interval

  • A detected change in the input signal

Block Inputs

This block has the following input ports:

Trigger Message

Manually triggers the message transmission when the input value is 1.

Signal For Change Detection

Detects changes in the input.

Block Outputs

This block has the following output ports:

Trigger Out

Outputs an active signal when a condition for triggering a message occurs. Connect this output to the Trigger input port of the J1939 Transmit Message block.

Block Parameters

Repeat on interval

Select this check box to enable periodic triggering at the interval specified in the Repetition Interval parameter.

Repetition Interval (ms)

Specify the enabled repetition interval in milliseconds. The repetition interval must be an integer multiple of the model update rate.

Send on a change in signal

Select this check box to enable triggering when both of the following are true:

  • Input signal wired to the Signal For Change Detection port input port changes by at least the value in the Minimum Change Threshold parameter.

  • Specified time in the Minimum Change Interval parameter has expired.

Minimum Change Threshold (%)

Specify the threshold change to trigger a message. The trigger event is a change in the input signal relative to the signal value from the previous triggering.

Minimum Change Interval (ms)

Specify the minimum time for the block to wait after a message transmission occurs because of a change in the signal.

See Also

External Websites

Introduced in R2009a

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