Hi Nico,
I was unable to locate a driver as well, however in your case, you are still in luck. www.ni.com/idnet has a driver for the Keithly 580. These drivers will almost certainly be nearly identical to the ones for your 590. I would recommend getting them and making the small changes necessary to make it support your 590.
Hope this helps Nico!
Best Regards,
Aaron K.
Application Engineer,
National Instruments
