ETTC'2003 - SEE

They however incorporate some elements,
which are normally less required in
commercial aircraft. The first being
environmental specifications. These
function units are available in three grades,
laboratory, extended specs or full
ruggedized specs with the explicit
requirement that the three versions must be
able to run the same application code. This
has led to the design of a new family of
hardware, which guarantee a total
reusability of the application software.
Another element is the size available for
the embarked computers, which has led us
to develop links to connect smaller units,
while maintaining the transparency and the
time information.
Finally CES’ new family incorporates new
hardware and firmware elements, whose
target is to monitor the safety of the
computer by providing on-line information
on the status of each element, so that
dynamic reconfiguration, of the whole or
part of the system, is possible during the
flight.
Introduction
Over the last 10 years CES has been
involved in both commercial and military
aircraft programs. In both fields the need
to reduce development time and unit costs
drives system designers to use COTS
rather than specialized developments
wherever possible.
Technology keeps evolving at a high rate
compared to the development cycle of an
aircraft. As an example, the IENA system
evolved from a prototype based on Mips
R3000 and Motorola 68040 processors at
25 MHz running LynxOS v 2.1 to a system
using PPC 750CX processors at 600 MHz
running LynxOS v 3.1. This evolution
spans three generations of processor
boards, each with its own characteristic
hardware architecture.
System design must therefore be made as
invariant as possible with respect to the
technology used to implement it. Useful
concepts for achieving this goal have been:
• The function unit
• The bundled package
• Hardware abstraction layers
Another characteristic of many aircraft
programs is a large variation in the
environmental requirements that systems
must meet. Most units of an aircraft test
system may be deployed in a laboratory
environment, but a few units of the same
system may be required to fly. Since an
ever-growing part of system costs go into
software development it is essential that
the software can be re-used in systems
with different environmental requirements.
In order to avoid excessive software
porting costs hardware platforms should
therefore support a wide range of
environmental specifications.
Working in both commercial and military
programs of aircraft development, CES has
acquired over the years know-how on both
sides, which can be used for the benefit of
the respective other field. Examples:
In the (commercial) IENA program,
experience gained in the construction of
(military) AGE systems based on boards
that are 100% software compatible to their
commercial-grade equivalents has been
used to build a test system that is running
the same software both in a laboratory and
in a test-flight environment.
In the (military) AIDASS test system,
BpNet, a hardware abstraction layer first
used during the modeling phase of the
(commercial) IENA system, has been used
to simplify the network cabling and thus to
considerably reduce the size of a portable
test system. The integration of the AFDX
test resource developed in the A380
context into the AIDASS system is in
progress.