If you are interested information concerning Registry Level Programming, it may be useful to visit our web page which describes our level of support and provides helpful information for programming:
ni.com>>Technical Support>>GPIB>>GPIB Register Level Programming
National Instruments also provides information for designing devices through our Resource Library:
ni.com>>Resource Library>>GPIB>>GPIB ASICs.
If you have more specific questions you may want to call Technical Support for information.
Best Regards,
Chris D
Applications Engineer
National Instruments