Hello, I now understand that the subVI has two inputs, the GPIB address and an error in cluster. So that doesn't seem like it could be any problem as you also suggest.
It's seems possible that since you have a while loop in this subVI, the data you are expecting to see coming out of this loop isn't right at all. If the output that displays the response from querying the instrument for the scan mode it is in is outside of the while loop, and then wired to the subVI terminal block, then you will not see that value until that while loop stops executing (assuming indexing is off). If in the VI, as a stand-alone VI, you are watching the response from the instrument on an indicator that is inside the while loop, or if the while loop stops executing as soon as that expected query gets executed, then you will see the expected response. Can you guarantee that the while loop stops executing after your instrument finishes executing the query for the scan mode it is in? Another think you might want to do is run the VI with the subVI in it with breakpoints set. This way you can step into the subVI and watch the execution of it as it executes the command. Then you can monitor the value being returned inside of the subVI instead of waiting to see the response that gets passed out of the subVI.
