When I hit the e-stop shown on page 3, that stops everything (motors, spindles, ALL) on the system.
When I eventually install my limit swithces in series with the e-stop as shown on page 3, the whole system will stop if, for example, my gantry hits the x-axis limit switch. Since the whole system is stopped, there is no way for me to jog back the gantry away from the switch. That's what the e-stop on page 1 is for. That e-stop allows me to connect pin 10 of the g540 to ground so I can jog back away from the switch. So it's not actually an e-stop. It's an 'e-enable'. ;-)