How to check a Cluster Refnum (strict) for validity ?

[dbaechtel]

I have a VI that loads a type def'd Cluster of data into a Front Panel Indicator from an INI file. I runs OK standalone.

I also want to use this VI as a subVI and to load a copy of the Cluster data into the calling VI using a Cluster Refum (strict) passed in by the calling VI. I can also get that to work.

The problem is that when the VI is run standalone, the Cluster Refnum (strict) input is invalid and I get an error 1055. How can I verify the validity of the Cluster Refnum (strict) input before I use it so that I can avoid the error 1055?

Thanks.

[tst · Accepted solution]

You can use the Not a Number/Path/Refnum? primitive from the comparison palette to find if a reference is valid.