NI Spy: Debugging Tool
NI Spy tracks the calls your application makes to National Instruments test and measurement (T&M) drivers, including NI-VXI, NI-VISA, and NI-488.2.
NI Spy highlights functions that return errors, so you can quickly determine which functions failed during your development. NI Spy can also log your program's calls to these drivers into a file so you can check them for errors at your convenience.