Transputer-based static data acquisition systems at DNW

Abstract

In general a substantial part of wind tunnel measurements consists of the acquisition of static signals. Static in this context refers to the slowly varying signals representing the steady conditions during a measurement. Recently the German-Dutch Wind Tunnel DNW has replaced its static data acquisition systems. The data acquisition hardware for two new systems has been delivered by the Dutch National Aerospace Laboratory NLR. The channel hardware is based on the proven concept of the NLR conditioning unit. This unit was selected by DNW because of its excellent analog characteristics. The unit type delivered to DNW is a further development of the generation of units in use at several wind tunnels (e.g. European Transonic Wind Tunnel ETW, Germany). This generation of conditioning units supports host computer controlled data acquisition but requires manual setting and adjustment of gain excitation voltage etc. The upgrade mainly consists of the replacement of this manual control by computer control. The internal control functions are performed by a special type of microprocessor (transputer). This microprocessor also performs initial computations on the digitized input signal. The systems have been fully operational since early 1995 and have fulfilled all specifications and operational requirements.