Hello TulioB,
Thank you for using our discussion forum. Trigger inputs, or high-speed captures, capture the precise position of the motion system when an external trigger signal occurs. You can enable or disable the trigger inputs from the Advanced tab under 1-D Interactive in Measurement and Automation Explorer. The trigger configuration can be selected on the Breakpoint and Trigger tab under Axis Settings. Trigger Input Occurred Led being red will not have any effect on the motion of your stepper motor. I hope this helps you out. Have a great day!
Regards,
Nipun M
Applications Engineer
National Instruments