ARINC 429 is one of the most prevalent specifications in use today for communicating between avionics components on commercial aircraft. It was created in response to lessons learned from the use of older equipment specified by ARINC 419. If you are new to ARINC-429 you may wish to check out our tutorial below.
Introduction to ARINC-429:
Excalibur Systems RTx family of products all support multiple channels of ARINC 429. Channels are software selectable to transmit or receive. Both High Speed – 100Khz and low speed - 12.5 Khz are supported as well as a variable speed for interacting with ARINC 419 compatible systems.
There are several modes that can be used for transmit channels that determine the timing method with which the data will be transmitted. Interblock Gap Mode transmits labels sequentially with gaps between labels in the order selected by the user. Frequency mode transmits labels based on a selected frequency – that is every n milliseconds. Multiple messages can be defined with different frequencies and the module will see to it that proper timing is maintained.
Time Tag mode enables the retransmission of a previously recoded session. The data, timing and errors of the recorded session will be precisely reproduced enabling one off situations to be reproduced. This can lead to a better understanding of the scenario and aid in debugging efforts.
Receive message have a 32 bit timetag associated with each label. Many of the modules can be attached to external Irig signals providing a timetag with a time of day format precise to the nearest microsecond.
Each channel may be received in its own buffer or all receive channels may be received in a single merged buffer. In either case, timetags of data received over all channels are based on the same clock aiding in the understanding of relationships between data received on each channel.
A special mode receives on one channel and retransmits on a paired channel with minor adjustments to the label or data such as changing the SDI or the label.
The same API can be used for the entire RTx family including the USB/Ethernet controlled UNET, miniPCI and miniPCIe and cPCI, PCI and PCIe.