Avionics Blog

In our previous post we saw how VME systems have not outlived their usefulness for MIL-STD 1553 and ARINC 429 test and simulation applications. However, their long-term future will continue to be threatened by end-of-life (EOL) of crucial subsystems and components such as the TSI148 VME-to-PCI bridge chip that’s been at the heart of VME adapter (carrier) boards. Some VME suppliers have left it up to their customers to address these EOL problems on their own. But for end users, dealing with VME platform issues is at best an engineering distraction. At worst, it requires them to decommission perfectly adequate VME systems and commit to the enormous expense of purchasing more up-to-date systems and porting legacy application programs to them.

After a successful multi-year collaboration and product distribution partnership, National Instruments will no longer distribute AIT's MIL-STD-1553, ARINC 429, and ARINC 664 PXI instruments after August 17, 2018. Despite the conclusion of this product distribution partnership, AIT is committed to the long term supply, support, and maintenance of all of our products including our PXI and PXI Express avionics interface instruments. AIT will continue to offer test instrumentation both directly and through multiple valued distribution channels and partnerships. (For a list of our North American Sales Representatives Click Here. For a list of our international distribution partners Click Here). AIT will always provide full applications support and maintenance services for all of our PXI products, including any AIT products purchased from National Instruments. We are also currently in the process of establishing new product partnerships and distribution channels for our PXI and PXI Express products, expect more details and a big announcement soon!

Back in 1979 VME began as a bus system for the Motorola 68000. Within a few years it became a standardized bus in Europe and North America (ANSI/IEEE 1014-1987). Since then, designers at military and civilian avionics suppliers have used the VME architecture in thousands of test and simulation systems, and many of these systems require MIL-STD-1553 and ARINC 429 avionics bus interfaces..

Avionics Ethernet

The use of Ethernet is becoming the more and more common in avionics network applications. As a result there are several adaptions and profiles of Ethernet, specifically for avionics applications that are becoming standardized in order to increase interoperability. This post is intended to provide a brief overview of the most common Ethernet adaptions currently utilized in avionics systems.

Bridging between legacy data buses and Ethernet

As more and more avionics systems begin to employ the use of Ethernet, there are an increasing number of application requirements for devices to operate as a bridge between Ethernet networks and MIL-STD-1553 bus systems. A few of the types of applications for MIL-STD-1553 to Ethernet bridges are:

Moving From Busses to Networks

As avionics systems move away from shared bus architectures towards more network based systems one of the key considerations for data acquisition applications must be the method of accessing the avionics system data. With shared data busses like MIL-STD-1553 and ARINC 629 monitoring equipment could easily access all avionics system data from a single connection to the shared bus. With switched networks there is no signle connection point with access to all data.

As avionics system have increased in complexity, so has the the demand for supporting networks that are capable of handling ever increasing amounts of data bandwidth. The table below provides a summary of some of the common avionics data bus and network technologies currently employed in aircraft systems.