Creating Custom Step Types that Call VIs for Substeps

When you create a custom step type that defines a Pre-Step, Post-Step, or Edit substep that calls a VI, you must create a source distribution to ensure that TestStand can resolve the file paths to all the dependencies of the VI when TestStand executes the custom step type. If you created the VI using LabVIEW 2010 or later, you can create a LabVIEW packed project library to consolidate all dependencies into a single file that the step type calls.

When you create a source distribution or packed project library, NI recommends that you enable the Always Run VI in LabVIEW Run-Time option in the LabVIEW Advanced Settings window in the TestStand Sequence Editor or on the Advanced Settings tab of the Edit LabVIEW VI Call dialog box in a TestStand User Interface to ensure that the VIs execute in the correct version of the LabVIEW Run-Time Engine.

If you do not create a source distribution or packed project library, LabVIEW browses its search directories to resolve the file paths to all the dependencies of the VI, which might break the VI.

Note TestStand supports executing a VI with a LabVIEW Class Reference parameter only when you execute the VI as part of a running sequence. Edit substeps and OnNewStep Custom substeps do not execute as part of sequence execution and cannot contain direct LabVIEW Class Reference parameters. If you need to pass a LabVIEW Class Reference, serialize the reference to a string parameter.