Testing Encoders

If the motion control system uses servo motors or closed-loop stepper motors, you must test the encoders. If the motion control system uses open-loop stepper motors, skip this procedure.

Complete the following steps to test encoders:

1. Power off the motors and drive. If you have a National Instruments nuDrive or MID drive, do not turn on the Enable switch.
2. Ensure that the encoders are powered on.
3. Launch Measurement & Automation Explorer (MAX).
4. Expand Devices and Interfaces in the configuration tree.
5. Expand NI–Motion Devices, and then select the item for the appropriate motion device.
6. Click Initialize.

   Note  This step assumes that you have correctly configured the initialization settings.

7. Expand Interactive in the configuration tree and select 1-D Interactive.
8. If you are testing a stepper motor, skip to step 11. If you are testing a servo motor, select the Main tab.
9. Move the motor manually in the forward direction. The encoder count increments in the position indicator. Move the motor manually in the reverse direction. The encoder count decrements.

   Tip  If you see the encoder decrement instead of increment, swap encoder cable A+ with A– or B+ with B–, but not both. If you have single-ended encoders, swap channel A with B.

10. Proceed to step 12.
11. If you are testing a stepper motor, ensure you have closed-loop selected as the stepper loop mode in the Main tab.
12. Select the Advanced tab and make sure the encoder position increments in the encoder indicator.
13. Repeat these steps for the remaining encoders.