Most of National Instruments DAQ DIO devices support TTL/CMOS logic. This means that they recognize low as 0-0.8V and high as 2-5V. I would first look at the user manual for a specific device to make sure it will work for your application, because different device have different specs (www.ni.com/manuals). The one catch is that they output 2.4-5 volts on the digital outputs, but if this is a problem you could use a zener diode to clamp the voltage to 3.3V.
I hope this helps.
Joshua Prewitt
