Emergency Stop Button

emergency stop or e-stop, is a safety mechanism used to shut off a device in an emergency situation in which it cannot be shut down in the usual manner. Unlike a normal shut-down switch/procedure, which shuts down all systems in an orderly fashion and turns the machine off without damaging it, a kill switch is designed and configured to completely and as quickly as possible abort the operation (even if this damages equipment) and be operable in a manner that is quick, simple (so that even a panicking operator with impaired executive function can activate it). Kill switches are usually designed so as to be obvious even to an untrained operator or a bystander. (Wikipedia....)