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J1939ILOnTxPrepare (Callback) CAPL Functions » J1939 » J1939 IL » J1939ILOnTxPrepare

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Function Syntax

long J1939ILOnTxPrepare( pg * txPG )

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Description

This callback function is called from the J1939 IL before a parameter group is sent. The signal value can be updated in the callback or sending of the message can be suppressed. Note Suppressing of AddressClaim and CannotClaimAddress Messages. Using this method you can suppress the AddressClaim or CannotClaimAddress messages as well. Please notify that in this case the corresponding node will switch to the next state (Active, Stopped or Initialized) even though the AddressClaim or CannotClaimAddress message has been not sent. You can use this method for the delaying of the AddressClaim message. Just suppress the AddressClaim message by the J1939 IL and send it some milliseconds later by the CAPL program.

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Parameters

  • txPG: message which should be sent

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Return Values

  • 1: send message
  • 0: do not send message

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Example

long J1939ILOnTxPrepare( pg * txPG )
{
  switch( txPG.PGN ) {
  case 0xFF01:
    txPG.BYTE(0) = 10; // update first byte
    break;
  }
  return 1;
}