E Stop Buttons

FluidNC does not directly support e-stop buttons. This is intentional. An e-stop button should cut the primary power. Relying on firmware defeats one of the primary purposes of having an e-stop.

Less Urgent Stops

If you want to stop quickly, but it is not a true emergency and the firmware is still running, you can use these alternatives. All of these can be sent via a gcode sender, the WebUI or a hardware button.

• Feed Hold. This very quickly stops the machine without loss of position. It can be resumed with cycle start. The feed hold command is the "!" character. The hardware pin setup with feed_hold_pin.
• Reset. This immediately stops the machine, but position is lost and you will need to re-home. The command is CTRL-X (0x18). The hardware pin setup with reset_pin.. This could be used in parallel with a true e-stop. The power will be cut and FluidNC will reset.
• Door/Parking. This feature is used for an enclosure door. If the door is opened during a job, the motion will quickly stop, the bit will retract, the spindle will stop and retract further from the work. The command is character 0x84. The hardware pin setup with safety_door_pin.

control:
  safety_door_pin: NO_PIN
  reset_pin: NO_PIN
  feed_hold_pin: NO_PIN