The benefit of using Commercial-Off-The-Shelf (COTS) Ethernet components is to lower overall costs for the aircraft network. Hardware components, cables and test equipment for Ethernet are field-proven and much more affordable than the previously used Avionics-specific solutions. Ethernet itself won't meet Avionics network requirements.
Therefore, ARINC 664 Part 7 extends the Ethernet standard by adding Quality of Service (QoS) and deterministic behaviour with a guaranteed dedicated bandwidth. This Avionics data network was first used in the Airbus A380 and A400M. Airbus and Boeing are extending the usage of ARINC 664 Part 7 in future developments continuously.
SYSGO's solution for ADFX® data networks is a pure software implementation that can be executed on standard COTS hardware. The implementation does not rely on an operating system as it comes with its own I/O and thread scheduler.
The layered approach simplifies porting and allows the re-usage of the existing certification documents.
The fields of application are manifold: The software stack can be used as stand-alone on a simple embedded controller that typically connects an end-system to the network. It might as well run inside a fully fledged end system, dedicated to a single processor core.
The use cases depend on the hardware design, number of virtual links and the targeted Safety level:
Connection of simple, yet critical end systems with a limited number of virtual links, such as landing gear or braking systems. Here, a complete implementation of the ARINC 664 standard would exaggerate the certification costs. The modular software stack can be tailored to the exact needs, providing a more appropriate lightweight solution.
An end system is physically located within a rugged environment (e.g. a jet engine) and the available hardware based FPGA/ASIC solutions do not fulfil the required specifications regarding temperature and vibration. In this case, SYSGO's software stack can be ported to a custom designed hardware.
Connecting digital field buses to the AFDX® data networks by means of a data concentrator. Inputs are typically coming from legacy systems such as CAN or ARINC 429 and require additional preprocessing. Here, adapted software is running on high performance computer boards.
Dedicated to a special operating mode with a low DAL Safety level, e.g.: data loading on ground. This allows to utilize the end system's host CPU instead of expensive hardware.
Power consumption, heat dissipation or size of hardware based solutions do not match the requirements: The software stack can be used in the context of a COTS computer board, e.g. beneath an operating system such as PikeOS. Both systems interact with each other by means of shared memory. On application side the AFDX® data network can be interfaced via ARINC 653 communication methods such as queuing and sampling ports. This allows multiple guest operating systems running on top of PikeOS to access the aircraft network in a deterministic way (graphical cockpit displays or fly-by-wire controls).
Ready for Take-Off
The software solution contains all necessary built-in self tests (BITE).
The AFDX® compliant network stack is certifiable according to DO-178C up to the Safety level DAL A.
Reference implementations, both for stand alone operation and in conjunction with PikeOS are available.
AFDX® is a registered trademark of Airbus.