This question come's mostly when none experienced people must be working with a pre congifured cnc machine.
It can be very dangerous to execute program's with external command's. Be aware of complete machine shield's or safety curtain's
conform depending country rule's.
The simple way is g-code with sub program.
This is also the safest. because you have to click on the screen.
When you have external start button's it's not the way for starting up with automated processes when you have none experience how to.
Only with fences around the machine you can sell or use this option. I have seen people killed by machine's with external start...
Search youtube. You see horrible things.
