If you don't care for the programming model you use, the POS prologix
usb adapter ought to be just fine.
but if you care about knowing when a device pulls-up the SRQ line in an
asynchronous manner rather than doing a busy-poll for discovering it
with a 1980s style master-slave I/O model, a proper NI board is what you
want.
Google ibnotify()
Nothing stops you from implementing ibnotify() on a background thread.
(Well, nothing except National Instruments' patent on the concept of a
callback function tied to a GPIB event.)
-- john, KE5FX
