Owning Palette: Comparison Functions
Requires: Base Development System
Returns TRUE if number/path/refnum is not a number (NaN), <Not a Path>, or not a refnum. Otherwise, this function returns FALSE.
Use this function to make sure a reference to an object, such as a VI, application, or control, still resides in system memory and was not closed.
The connector pane displays the default data types for this polymorphic function.
|number/path/refnum can be a scalar number, path, or refnum, or it can be a cluster or array of numbers, paths, or refnums.|
|NaN/Path/Refnum? is a Boolean value of the same data type structure as number/path/refnum.|
This function works only on references generated by LabVIEW functions. Do not use this function to determine the validity of a rendezvous refnum, semaphore refnum, or any refnum created by the GOOP wizard, LabVIEW Database Connectivity Toolkit, or LabVIEW Internet Toolkit. For rendezvous refnums, use the Not A Rendezvous VI. For semaphore refnums, use the Not A Semaphore VI. For all other GOOP refnums or toolkit refnums, use the Vis defined by the refnum creator.
To avoid race conditions when evaluating the refnum status, National Instruments recommends limiting the usage of this function in the following ways: