An overview of a Labview / Teststand test system design that is object oriented and allows the use of VB Scripting. It gives a description of the classes to used and the model for the overall design.
The Test Structure is designed to conform to the Microsoft .NET Environment while not imposing unnecessary requirements. The design process uses the class objects to create a modular “from the bottom up” platform. Using an Object Oriented structure the LabVIEW CORE consists of classes for IO, Instrument, Measurement and Test. The TestStand core classes include the Test.Subsequence, and the TestCase.Sequence.
It is very adaptive and does allow for the use of VBScript It is also easily adapted to allow for the other popular scripting languages i.e. PERL, TCL or Atlas. However, most applications will use the inherent ability of TestStand™ to run inclusive test cases. The suggested interchange with VBScript will be thru a .DLL call within TestStand™, which launches and instance of VBScript.engine. The method is well documented with National Instruments.
The Object structure implies all test system classes to be stand-alone applications. However, most VI’s will not be used individually in the proposed design and only selective classes will be public. If direct control of VI’s is needed, a client-server environment will be created. LabVIEW will launch an instance of VBScript Sever, which will handle script feeds. The script control will be limited to control of an instance of the Main Operator Interface and will use the GET and SET Active X control functions. The design eliminates the need for VBA.
The system provides a test platform that is easy to deploy in the development and production areas. The GUI is intuitive to operators. Interchange of instruments is seamless which should help decrease maintenance costs and increase the capacity to complete tests. This architecture provides the user a GUI to assemble and configure new types of tests. Data Limit testing is automated and test/evaluation and the final test results for the future analysis are all configurable within a GUI.
It is easy to understand the function of the modules of LabVIEW and to carry out the modification of these modules. The configurable instance of test case makes it possible for the user to configure test parameters in the immediate mode with no additional programming. When the user configures a test case, they have the capacity to place test parameters while visualizing how these parameters affect the statute of test. The configurable stages of test provide to the user a graphic user interface (GUI) to configure the test parameters. Based within test several configurable types of test can be developed to take measurements. It is easy to deploy the development of new products because it adapts to changing test parameters, modifies the flow of execution, and looks at monitor system variables.