MID-7602/4 Not Outputting Voltage to Motor

Updated Apr 6, 2020

Reported In


  • MID-7604


  • LabVIEW SoftMotion Module

Issue Details

When I initialize my code to begin moving my stepper motors, the code doesn't error out but my stepper motors don't move. The Fault indicator lights are all lit up as well as Inhibit lights. What can I do to resolve this issue? 


The first thing you need to check is to make sure the Host Bus Interlock Circuit isn't active. The host bus interlock circuit monitors the +5V signal from the motion controller to check if the controller is powered and properly connected to the drive. Verify that the controller is powered and properly connected to the drive. Next, follow these steps to verify that the MID is still operational:
  1. Disconnect all cables and wiring from the back panel of the unit.
  2. Remove the controller cable and all motor, encoder, and limit switch wiring.
  3. If the fault light(s) are still lit after removing all wiring from the drive, verify that the voltage input setting is correct for your area (120V/240V).
  4. If the fault light(s) are still lit, you can stop here. The drive must be either repaired or replaced.
  5. If removing all of the wiring causes the light(s) to go out, then try connecting cables one at a time to locate the problem. If the problem occurs upon connecting the 68-pin cable, then it's possible the cable is bad.
  6. Make sure it is connected to the Motion IO connector on the controller and not the Digital IO connector. If the lights come on when you plug in the motors, check for short circuits.

Additional Information

Since this device is EOL from National Instruments, there won't be any way for to repair or replace this part from National Instruments side. It may be necessary to consider third-party options to best fit the future needs of the system.