This is supposed to end up with the string indicator being labeled "C", but it doesn't.
If you're updating the caption, maybe you don't have it visible? (I'm guessing "caption" because you didn't mention an error, which you surely would've gotten if you were actually updating the label.)
Do you happen to have automatic error handling turned off? The error message will tell you what is wrong. I am not sure if "Beschriftung" corresponds to Label or Caption. Only caption is writable during run-time and only if it was created at edit-time.
@all: It's german LV, but there "Beschreibung", which is supposed to be the description is the default label you see when placing an indicator. I also enabled the "Untertitel" (caption?) and did both, with the same result.
@cordm: no. The word label is the superior term for captions, subtitles and descriptions.
You cannot edit the label (Beschr.Text) at run time!
The later items in your property node won't be executed because the first one errors out.