Analog Input >> General Properties >> Signal Conditioning >> Excitation >> AC Excitation >> Frequency

NI-DAQmx C Properties

Analog Input >> General Properties >> Signal Conditioning >> Excitation >> AC Excitation >> Frequency

Data Type: float64
Description: Specifies the AC excitation frequency in Hertz.

You can get/set/reset this property using:
  DAQmxGetAIACExcitFreq
  DAQmxSetAIACExcitFreq
  DAQmxResetAIACExcitFreq