Developing portable test program sets in a graphical design environment

This paper describes techniques for reducing test station hardware dependence in test programs implemented in National instrument's LabVIEW development environment hardware dependence is reduced by a combination of design strategies, and by the definition of a Hardware Abstraction Layer (HAL). The HAL reduces hardware dependence by insulating the developer from the test station resources, by encapsulating the hardware drivers supplied by the equipment manufacturer with wrapper functions. The HAL allows the TPS to be partitioned into hardware dependent and independent components, localizing the hardware dependencies in the HAL wrapper Vis. This paper also describes a method using hardware configuration tables to effectively defer binding of test resources until program execution. This technique allows the TPS to compensate for minor changes in hardware configuration without having to edit or recompile any LabVIEW code.