Developing engine test software in LabVIEW

Abstract

CACI International Inc. is on contract with SAALC/LDAD, the Air Force engine tester program management office, to build an Engine Test/Trim Automated System II (ETTAS II) using Commercial Off The Shelf (COTS) hardware and software. This tester will ultimately replace the three aircraft engine test systems currently used by the Air Force, all of which are becoming increasingly difficult to maintain doe to hardware/software obsolescence problems. In keeping with the COTS requirement, we chose to develop our data acquisition and test program software in LabVIEW 4.0.1 for Windows NT/95. This paper discusses the advantages we have gained in using LabVIEW 4.0.1, a graphical programming language, rather than a conventional programming language as our software development environment. We detail how we were able to take advantage of LabVIEW's instrument control capabilities to optimize our VXI data acquisition process. We then discuss how LabVIEW can be used not only as an instrument control language, but also as a general purpose programming language. We discuss how we used LabVIEW for test program set (TPS) development and for rapidly prototyping user interfaces and program features for immediate operator/customer feedback. The paper also details how LabVIEW enabled os to readily establish a core of "generic" VIs (virtual instruments) for subsequent reuse in developing additional TPS for other aircraft engine types/variants.