Giulia - You are correct. The NI-4472 is not supported in DAQmx 7.1 so you will have to use Traditional DAQ. There is a shipping example called Acquire N Scans Digital Trig.VI. If you open this VI and designate some pre trigger samples, your trigger is now a reference trigger instead of a start trigger since you will acquire data before the trigger arrives. This is the same for an analog trigger as well.
If you are using something other than LabVIEW, look ate one of the shipping example for Traditional DAQ which uses triggering and just specify your pre trigger samples. Hope this helps. Jack Application Engineer National Instruments
