• APPLYING RULES FOR ISOCHRONOUS SAMPLING WITHIN ACQUISITION CYCLES TO ALL LEVELS OF FTI SYSTEM DEFINITION

      Fielding, Richard; McNelis, Aaron; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      This paper examines two rules for data acquisition that have advantages for today's Flight Test Instrumentation (FTI) systems where: • Data is acquired from physically separate test equipment • Deterministic (IRIG-106 (Ch. 4)) and non-deterministic networks co-exist • Data Acquisition Units (DAUs) from multiple vendors are required • Signal lists and sampling rates change rapidly • A time-coherent sampling strategy (even for smart sensors) is required These rules may aid not only in the selection of the data acquisition equipment but also the definition of the sampling, transmission, storage and analysis strategies.
    • DEFINING AN OPEN FLIGHT DATA ACQUISITION SYSTEM

      Corry, Diarmuid; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      As today’s flight test data acquisition systems grow more complex, there is an urgent need for open standards that allow Commercial Off-The-Shelf (COTS) equipment from different vendors to be used together. However, there is more to inter-operability than getting the wiring right – it flows through from requirements specification to the gathering of data. This paper discusses the characteristics of an open system at each interface between customer requirements and programming of the Data Acquisition Unit (DAU): • Industry standard specifications for data interchange with databases and software packages • Human readable file formats for Data Acquisition Unit (DAU) setup • Communications link from ground station equipment to DAU • Industry standard protocols for interconnection of DAUs • Intra-DAU backplane specification to allow custom acquisition functionality to be added Only by providing third-party entry points at all five layers can the goal of an open data acquisition system be achieved.
    • SIGNAL PROCESSING ABOUT A DISTRIBUTED DATA ACQUISITION SYSTEM

      Kolb, John; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      Because modern data acquisition systems use digital backplanes, it is logical for more and more data processing to be done in each Data Acquisition Unit (DAU) or even in each module. The processing related to an analog acquisition module typically takes the form of digital signal conditioning for range adjust, linearization and filtering. Some of the advantages of this are discussed in this paper. The next stage is powerful processing boards within DAUs for data reduction and third-party algorithm development. Once data is being written to and from powerful processing modules an obvious next step is networking and decom-less access to data. This paper discusses some of the issues related to these types of processing.
    • SPECIFYING A PCMCIA IRIG-106 (Ch. 4) DECOMMUTATOR

      Mc Girr, Niall; ACRA CONTROL INC (International Foundation for Telemetering, 2002-10)
      There are many applications where an ultra-compact PC (palm-top) is required for quick analysis of PCM data. There are many design issues associated with the design of a PC-Card (PCMCIA) decommutator. • Is it possible to connect a 20Mbps PCM stream? • What outputs are required from such a card? • How many cards can be used? • Which mode to use (memory or I/O) • How to program such a card • How to develop third-party software for analysis of data This paper discusses some of these issues and the applications for such a card.