Changing the Automatic Test Paradigm Through Concurrent Measurement and Test Development

摘要

Industry has traditionally provided Automatic Test Equipment (ATE) and Test Program Sets (TPSs) that are based upon sequential signal measurements followed by an evaluation. For example, in a traditional TPS a signal is captured and evaluated and if a NOGO condition exists the next signal measurement is made as part of the diagnostic path. This common approach raises two issues, fault isolation accuracy and runtime. Acquiring diagnostic signal measurements after a failure is detected may not capture the real "snapshot" of the system and may result in inaccurate fault isolation. In addition, capturing the additional signals during diagnostics increases runtime. Industry has also accepted that software, specifically test software, is primarily based on a procedural language. A procedural language raises at least four issues: the lack of a Rapid Application Development (RAD) environment, the time and skill level to generate the software, the potential need for a compiler and error checking. In early 2002 SEI was awarded a contract to develop the next generation Contact Test Set to be used in testing the LAV-25 Turret assemblies. This program required rapid development of a test station and TPSs that provided highly reliable fault detection and isolation and short runtimes. To achieve this SEI developed a unique test system, which used commercial off the shelf hardware, that supported capturing signals concurrently. In addition, a new declarative test language, which relied heavily on templates and pull-down options, was defined. This declarative language approach provided the RAD needed to meet the development and integration schedule.