Dear DimasRex,
I might be wrong, but it sounds like you forgot to include the instrument driver's header file in your source code. Once the instrument driver is loaded in your project (including all the instrument driver files will load it automatically) the final step is to include the header file that contains all the function declarations in your code. So, this will be the #include "nameofheader.h" statement.
Regards,
Azucena Perez
Measurement Studio Support Engineer