Hi Mattyd,
More information about this function is located in the NI-DAQmx C Reference Help. You can get to this by going to Start >> All Programs >> National Instruments >> NI-DAQ >> NI-DAQmx C Reference Help. Once the document is open, go to NI-DAQmx C Properties >> List of Read Properties >> Available Samples Per Channel.
Regards,
Hal L.
