DAQmx 1D waveform NChan NSamp vs Duration?

[flycast]

What is the difference between DAQmx 1D waveform NChan NSamp vs DAQmx 1D waveform NChan Duration? The documentation does not seem to document the duration version.

[crossrulz]

Yeah, that's a limitation in the documentation.  My understanding (I have not used this exact function) is that it will read the number of samples in the given duration.  I guess it makes things a little cleaner in that you don't have to do the math to figure out the number of samples in a given time (as most of us do in order to have a set loop rate).