Fabio,
Currently FieldPoint Explorer only allows one instance of the FieldPoint Server to launch at a time. Thus the first FP Open.vi that you call will open the FieldPoint Server with IAK1.iak and when you try a second FP Open.vi with IAK2.iak, the return code is successful since the FieldPoint Server is launched, but it is still using IAK1.iak. If you want to use two separate IAK files, you would need to run the FP Close.vi to close the server prior to re-launching it with the second IAK file. Alternatively, what may be better for you is to create a Data Server application, that can handle using a single IAK to talk to either bank of FieldPoint modules and makes the data available (via datasocket, globals, FIFO's, etc...) and then your programs just talk
to the data server and do not have to worry abouth whether the other VI is running or not.
Regards,
Aaron
LabVIEW Champion, CLA, CPI