Driving and dimming LEDs with USB-6501

I have a strip of LEDs hooked up to a power source with an intermediate dimmer. The specs for all that hardware is listed below. I am looking to switch from manual control to digital I/O. I have a NI USB-6501 DAQ but have never worked with it before and so would appreciate some guidance. The goal is to maintain maximum brightness but be able to dim the LEDs from my software. I've read several threads about simple on/off control but haven't found anything on dimming.

John.

LEDs: (color red)

http://www.superbrightleds.com/moreinfo/led-strips-and-bars/snfls-series-120-side-emitting-led-flexible-light-strip/1657/#/tab/Specifications

Dimmer:

http://www.superbrightleds.com/moreinfo/single-color-dimmer-switches/ldp-2a-12-volt-dc-single-color-led-dimmer/61/

Power Source: (15 Watts)

http://www.superbrightleds.com/moreinfo/power-supplies/12vdc-cps-series-power-supply/68/