Hi,
An E-Stop removes power from everything, not just the output devices, but also the input devices.
An E-Stop is unconditional, you may want to hit the E-Stop because;
- An output device , motor, valve, light has malfunctioned.
- A process is out of sync.
- A life is in danger, electric shock, caught in machinery, hazardous situation occurs.
- An input device has failed.
- Controller fails.
- Power supply fault.
Everything has to shut down.
Tom... 