https://forums.ni.com/t5/LabVIEW/How-to-know-if-a-wire-is-connected-to-a-control-in-the-case-of/m-p/3848117
Solved: Re: How to know if a wire is connected to a control (in the case of subVI)? - Page 3 - NI...
Oct 11, 2018 - Good stuff... for many data types. But boolean controlse sure present a challenge to employ this strategy