Hello Yang Xin,
If you are trying to access third party external code from LabVIEW RT, we cannot support that as described in the KnowledgeBase I linked earlier. As the KnowledgeBase says, "We do not offer LabVIEW RT support for applications that call external code. You can link the third-party instrument driver code to your LabVIEW RT application via Call Library Nodes, but we cannot guarantee that all the functions in the external code will be supported."
In the document you referenced for creating your own inf file, it was describing the first steps toward writing your own device driver using VISA to access the registers on your device. It's sounding like you are still trying to access a third party driver.
If you
can clarify what the situation is, perhaps I can provide more assistance.
Regards,
Kristi H
National Instruments