Are trying to generate the signal with the 1411 or recieve a trigger?
If you are doing a triggered acquisition, then I would start with one of the LabVIEW IMAQ shipping examples, such as HL Triggered Snap.vi. Make sure you have the polarity set correctly and are not receiving pulses faster than the camera is acquiring.
If you want to generate a signal from the IMAQ board, then you will need to use IMAQ Trigger Drive. The 1411 cannot generate pulses using the IMAQ Generate Pulse VI.
Regards,
Brent Runnels
Applications Engineer
National Instruments