What you see here is, I installed 4 switches. each have individual sockets directly under them. The E-Stop is in series with the router hot wire. My E-Stop button has 2 separate sides one goes to the mains with the router the other is connected with smaller wire to the E-Stop pins on the controller board. When I hit the button the router stops and so does the controller. It DOES NOT power off the controller board it DISABLES the motors instantly via the controller board estop pins. I can power off the router with the switch on top and at that point reset the E-Stop button. This releases the motor disable. Unfortunately you will still have to RE-HOME after that event happens but I don’t have to re-connect my computer or software to the board at that time I just hit the home button.
It’s just an extra set of wires running off one side to the controller board this way.
Mine is here:
https://www.amazon.com/gp/product/B01BLJ6ES0/ref=oh_aui_detailpage_o06_s01?ie=UTF8&psc=1
One side is normally closed (This side is mains to router)
The other side is normally Open (This side to E-Stop pins)
When you hit the button the router side breaks. The e-stop pin connects and when it connects is releases (disables) the motor driver circuits.
I hope that explains it, if you have questions let me know.