The code you have is correct and I have used that same sequence in other VIs without any issues at least on TestStand 2014.
I noticed that if you create the StationGlobal in the 'Variable View' of the sequence as you showed, you must also go to the View -> StationGlobals entry and SAVE the 'Globals'. If you don't save it, I got the same '0' result on a test that I did. Although I also had an error saying the LookupString was 'invalid' , which makes sense because I had not saved it yet.
Did it return any errors or was the value just zero?
~Teds
