Analog Input >> General Properties >> Digitizer/ADC >> Raw Sample Size

NI-DAQmx C Properties

Analog Input >> General Properties >> Digitizer/ADC >> Raw Sample Size

Data Type: uInt32
Description: Indicates in bits the size of a raw sample from the device.
Restrictions: Not Settable

You can get this property using:
  DAQmxGetAIRawSampSize