Sending Messages

There are two basic ways to send ARINC 429 32-bit words on a given channel: aperiodic and periodic transmissions.

• aperiodic transmission

  Aperiodic Transmission is used to send one or more ARINC 429 words encapsulated in a MXF_A429_DATAREC transmission unit.

  The ARINC 429 words are sent to one of the three priority queues.
  The precise timing when each ARINC 429 word transmission occurs can be defined using the time tag field.

• periodic transmission

  Periodic Transmission is used to send ARINC 429 words on a given channel using the device onboard scheduler. The device scheduler performs the repetitive transmission. The buffer contents can be periodically updated by the host application.

  The ARINC 429 words are sent on the normal priority queue.

Error Injection can also be used to inject errors in transmission.

Configuring Transmit Channel

The first step when writing a ARINC 429 application is to configure the transmission channel.

Refer to the example '429 channel attributes' for an example on how to start an application and locate and set the transmit / receive channels.