Instrument handles

[jay]

Hi all,

Im totally new to LabVIEW and I was wondering how to determine programmatically whether a handle for an instrument exists.

Essentially I have a VI that can be called to initialise, measure, and close a DMM - and the handle is stored in a shift register. However I want to use the DMM in multiple parts of my program. I need to determine whether the DMM has been previously been initialised i.e. if the handle already exists.

I guess I can do this by determining whether the handle is and empty string. But is there a more efficient way of doing this?

Oh and just in case, im running a PXI system - not too sure thats relevant.

Thanks.