Counter Input >> Position >> B Input >> Terminal

NI-DAQmx C Properties

Counter Input >> Position >> B Input >> Terminal

Data Type: char*
Description: Specifies the terminal to which signal B is connected.

You can get/set/reset this property using:
  DAQmxGetCIEncoderBInputTerm
  DAQmxSetCIEncoderBInputTerm
  DAQmxResetCIEncoderBInputTerm