Abstract
One of the crucial points in the development of an experimental-test system is coordinating the acquisitions from the many connected measuring instruments. In general, there are two ways of addressing this issue, based respectively: (i) on an ex-post synchronization of the readings previously gathered during the tests, or (ii) on a properly-said synchronization of the instruments during the experimentation.
The first approach can give interesting results, even if it can be computationally heavy, having the experimenter to manage files with different formats, with data coming from instruments with different sampling frequencies and, maybe, having also non-synchronized internal clocks.
The second approach is certainly more effective, allowing the user to have, just at the end of a test session, ready-made data for any subsequent processing phase. However, it needs a lot of work for its implementation. Indeed, it requires the set-up (or the creation) of many hardware interfaces, the writing of software and, possibly, also the implementation of a simple and reliable user interface.
Such this latter approach has been followed in the creation of the control subsystem of the integrated test-system for agricultural machines, part of the equipment of the “Agroforestry Innovation Laboratory” of the Free University of Bozen-Bolzano. This management subsystem, based on Labview, has a graphical user-interface able to: (1) simultaneously acquire data from a trailed PTOdyno, a fuel-consumption meter, an exhaust-gas chemical analyser, a datalogger with different thermocouples, (2) display in real time the value of the acquired quantities, (3) plot in real time the motor-performance graphs (torque, power as a function of engine speed) and other time-dependant graphs, (4) save the acquired data in a format compatible with the most common spreadsheets. After illustrating the main features of this acquisition system, we presented also its successful application in the test of a New Holland T4020V tractor.