A Discussion About a Distributed DAU Standard

Abstract

Modern aircraft are both bigger in some dimensions and smaller in others than previous generations of aircraft. With earlier airplanes we were able to centrally locate a data acquisition system and bring wires from all of the transducers to a central location. With more recent airplanes two factors have combined to make this impossible. First, each new program requires more transducers and thus more cables: it is no longer possible to bring that many wires to a single location. The other problem is that airplane wings and control surfaces have become thinner leaving less room for cables. To date we have been able to get around the problem by using physically small Data Acquisition Units (DAUs) that are distributed around the aircraft. However, it is now reaching the point where the space available in the airplane to run wires is becoming so limited that we need to use DAUs that have a small number of channels as well. What is being proposed is that the test community develop or adopt a standard that will allow systems to be built that look to the higher level elements of the system as a single DAU but in reality are composed of several small nodes that are distributed around the airplane and connected by some communications medium.