Check out these Developer Zone Examples for using UIMessages to implement a progress bar. These examples implement a progress bar that can be used for long executions without processor intensive polling or the risk of blocking correct termination.
Developer Zone Example: Launching a Floating LabVIEW Panel in TestStand
Developer Zone Example: Launching a Floating .NET Form in TestStand
Developer Zone Example: Launching a Floating CVI User Interface in TestStand
Evan Prothro
RF Systems Engineer | NI