Analog Input >> General Properties >> Signal Conditioning >> Excitation >> AC Excitation >> Synchronization Enable

NI-DAQmx C Properties

Analog Input >> General Properties >> Signal Conditioning >> Excitation >> AC Excitation >> Synchronization Enable

Data Type: bool32
Description: Specifies whether to synchronize the AC excitation source of the channel to that of another channel. Synchronize the excitation sources of multiple channels to use multichannel sensors. Set this property to FALSE for the master channel and to TRUE for the slave channels.

You can get/set/reset this property using:
  DAQmxGetAIACExcitSyncEnable
  DAQmxSetAIACExcitSyncEnable
  DAQmxResetAIACExcitSyncEnable