Pitfalls of Plug&Play

The VXI Plug&Play Systems Alliance sought to make VXI systems easier to build and use. However, a misleading picture may have emerged as to both the relative level of complexity and the propensity towards undesirable effects in both creating and maintaining an ATE system. This paper will attempt to identify some of the pitfalls of Plug&Play. In terms of the complexity level aspect, a misleading picture may have been painted as to the creation of an ATE system. The VXI Plug&Play picture is often depicted as a potential user merely selecting stimulus and measurement instruments and creating a truly effective ATE system with little or no resulting problems. This might indeed be the case for a limited suite of relatively simplistic UUT. However, for more complex UUT there are a host of issues which can make if difficult if not impossible, for even the most capable engineer to assemble a successful ATE system if his or her team does not have extensive experience in ATE systems design, development and integration In addition, other undesirable effects can occur. First of all, not every OEM produces Plug&Play code. The use of Plug&Play does not support the concept of "open systems" since it is invariably LabVIEW or LabWindows with other compilers/environments rarely supported. Plug&Play does not promote the ability to share code and does not promote good coding techniques. There is no warranty for the code to be bug free and no guarantee any fixes of such bugs will not create other problems. Software maintenance is more expensive in the long run due to a disparity in coding techniques. As each new Plug&Play code is used in a system the learning curve for maintenance personnel must be extended, with this increased burden pertaining to both TPS and system utilities.