Can't Read Quadrature Encoder Z Index in NI-SoftMotion

Updated Feb 1, 2018

Reported In


  • NI-951X
  • C Series Motor Drive Interface Module


  • LabVIEW SoftMotion Module


  • Quadrature encoders

Issue Details

I can't properly read the Z index of my quadrature encoder in NI-SoftMotion. What can I do to troubleshoot this issue?


  • Check your quadrature encoder signals for correctness using an oscilloscope or other digital input device.
  • If you're using a Drive Interface Module (NI-9512, 9514, or 9516), refer to the manual of your device for the proper wiring: NI 951x User Manual
  • Ensure that you've selected the correct encoder for your axis in your LabVIEW project by right-clicking your Axis and going to Properties » General Settings.
  • Ensure that your encoder settings match the specifications provided by your encoder manufacturer in the Encoder Settings tab.

Additional Information

SoftMotion only uses the A and B indices of a quadrature encoder for position feedback. The Z index can be used for Index Reference Moves, as seen in the Reference Move Mode documentation.


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