I've created a waveform using NI Digital Waveform Editor, but I want to repeat it N times in quick succession using the PXIe-6556.
Using LabVIEW 2011, I've tried this in software, placing a "for" loop around "initiate" and "wait until done" HSDIO blocks. This is a software regeneration of the waveform though, and is nondeterministic. The gap between sequential runs of the waveform is arbitrary.
Is it possible within digital waveform editor to define the waveform once, and then get it to generate N repeats of the waveform in the one HWS file?
Try the niHSDIO Configure Generation Repeat VI (found in NI-HSDIO > Generation > Configuration palette.
You can use this to set up finite repeats, one of the inputs is "N".
This creates hardware timed waveform repeats instead of software (which is as you have seen very slow and unreliable due to OS being in control).