How is RAW mode exactly implemented?

Hi, I'm trying to implement waveform capture on DS4052 for scientific experiment. Waveform download in normal mode works but raw gets stuck after dozen of bytes in transit. I assume I'm making some stupid configuration mistake.

I tried searching through codebase but was unable to quickly find exact visa instruction order. Would you be so kind and share how exactly are you talking to oscilloscope to get it to return entire buffer?