I am trying to capture data off an oscilloscope and write to a csv or txt. So why is "Excel" in the title of this Post? You are writing a text file, possibly as a Comma-separated Values format.
I have tried adding an invoke node but it doesn't allow me to add notes, timestamp etc. Why are you telling us this? There are many things that won't work ...
I have attempted to use waveform to spreadsheet.vi but some reason the spreadsheet string is grayed out. How can I enable it? I don't see this function, so can't see what (presumably illegal) thing you wired to it.
Currently the vi runs and doesn't stop... When it runs, what does it do? Does it write anything? Does it "stall"? Where does it get stuck? [I see no loop, so it must stop somewhere -- can you pinpoint the place it gets hung? Where is the "sticking point"?