PCM to Ethernet: A Hybrid System Used to Certify the Next Generation of Data Transfer Technology

Abstract

The last few years has witnessed the adoption of Ethernet technology in an increasing number of FTI applications. This is a result of both the growing acceptance within the community of the application of the technology, the availability of suitable hardware and the desire for increased parameters/higher data rates that PCM is unable to accommodate. However, migrating from an existing PCM based networked system to Ethernet is not typically just a case of exchanging the necessary hardware. There can be a range of other issues that require addressing such as ensuring determinism and realizing previous investment in hardware - this paper highlights and discusses several of these. This paper presents a case study of an FTI application on the Embraer Legacy 500 where a hybrid PCM and Ethernet configuration was implemented. One reason for this configuration was that it was necessary to prove to the Brazilian Aeronautical Agency that the data acquired using an Ethernet system was as reliable as that acquired using PCM. An additional reason was that such a system was seen as a safe stepping stone to a full Ethernet system for programs in the near future which are planning to fully migrate to an Ethernet architecture.