Hi Curious-
The driver you're looking for is DAQmx Base 1.4 for Linux. It is available for download here:
DAQmx Base 1.4 for LinuxIn Linux, the driver supports the following features for the USB-600x (information from readme file):
NI USB-6008/9
*Analog Input
-Digital start triggering
-Multi-channel, multi-sample read (scaled)
-Multi-channel, single sample read (scaled)
*Analog Output
-Multi-channel, multi-sample write (scaled)
-Multi-channel, single-sample write (scaled)
*Counter Input
-Simple event counting (falling edge only)
*Digital I/O
-Line input
-Port input
-Port output
-Line output
Regards,
Tom W
National Instruments