Very new to Labview (student). I built an application (my first)that uses VISA serial in Labview 7.1. The application contains a VISA resource name control. The program worked when silmulated, but not when built as app. When I removed this control from the application and made it a constant - the app worked. Any reason for this? A way around it perhaps? Would love an answer. I did make sure the Run-time engin is correctly installed and that it is not the problem. Thanks, Madri