| Stop | Wired into the unit's own safety controller | no software in the path; it stays down once pressed, with a pull-lanyard wired into the same path |
| Manual release | On every actuator: one hand, no tool | performed by a spring, so it releases with the air gone and the power off |
| Clearing a stop | A person at the machine, with a separate reset | no stop is cleared from a distance, by a clock or by a message |
| Independent safety controller | Its own hardware, power and wiring | it can hold the machine, take run permission away, dump the energy and prove neutral; it cannot start, arm or grant authority |
| Loss of power to a safety output | Falls safe | by spring or by design; holding the machine anywhere else takes power |
| Approach sensing | On the machine, wired | a person inside the zone stops the machine, and a person at the machine clears it; it can remove authority and never create it |
| External sensing | Can remove authority; never creates it | a clear picture is never a reason to proceed |
| Task safe states | One of three, set per task before the call | never improvised; stopping in place is not always the safe answer |
| After the safe state | The minimum-risk condition, then a person is called | whichever safe state the task reached |
| Degraded state quality | The task slows, stops, asks for human review or prohibits the skill | below the threshold set for the task; unknown state is a valid state |
| The machine's own safeguards | Left in place and working | seat belt, lockout lever, park brake, horn and lights checked working at every pre-start |
| Lockout and tagout | A written procedure | for service with the unit fitted, and for stripping the unit and the dock off a machine |