NI-9512 Does Not Step in Reverse

Updated Jun 7, 2018

Reported In


  • NI-9512
  • cRIO-9066


  • LabVIEW
  • LabVIEW SoftMotion Module

Issue Details

My NI-9512 stepper drive was configured and working. It seems to have stopped working after wiring optical limit switches. Seems to move in reverse (CCW) OK. It creeps backward slowly when told to go forward. I measured .5V to ground when enabled (should be sinking 5V from drive), 0 V when disabled. Voltages on direction output 9.5V when should be moving CW, 4.5 when moving reverse. Is my 9512 broken?


While possible, the problem is more likely with physical wiring to the NI-9512. Follow these troubleshooting steps to rule out problems with the device:
  1. Try moving the module from one slot to another in the CompactRIO.
  2. See if the behavior persists when using the Interactive Test Panel in your LabVIEW project.
  3. Test the electrical signals coming from your 9512:
    1. Remove everything but the connections to the 9512 from your breakout.
    2. Use a multimeter to probe the Enable pin and COM.
    3. Enable and disable the axis on the 9512 in software. You should see the Enable LED light up on the module, and the voltage between Enable and COM toggle between the power supply voltage and zero. 
  4. If you have another 9512 available, try swapping them out. If the issue persists, the problem is likely not with the module.