12 — Safety
The belt and the arm move. Read this before either is powered.
SE Inspect is a research and alpha system. It has no safety rating (no performance level under ISO 13849, no SIL). Every safety function you need must exist in hardware, independent of this software. The software contains protective logic (below), but protective logic in an alpha is not a safeguard.
Before the belt or the arm is powered
- An emergency stop that cuts the 12 V of belt and arm, within reach of the operator's position.
- The relay on the NO contact, so that a crashed Pi or a pulled cable stops the belt.
- The arm's working envelope clear of hands, cables and cameras; end stops working (
endstatin the firmware) before the first homing; motor currents set for your motors. - No loose sleeves, no fingers in the pickup zone while the line is active. The arm calls "Holen" automatically whenever a known part is stable in the pickup zone for 0.35 s.
- The Pi on its own supply; belt and arm supplies fused.
What the software does — and what it does not
Built in: an unknown part in the pickup zone stops the belt and never calls the arm; without working recognition the belt does not run; stopping the line asks for confirmation because it interrupts a cycle; a hung card takes itself out of the pool rather than blocking the loop; the empty-belt guard refuses to learn "nothing" as a part.
Not built in: any person detection, light curtain, safe torque off, or watchdog on the arm's motion. If the network drops, the UI shows "Bildverbindung unterbrochen" — the machine state continues on the Pi.
Electrical
12 V circuits with a 3–5 A fuse, common ground with the Pi, flyback diode across the motor with the stripe towards +, reversed diode = short circuit. Never route 12 V through the Pi. Cameras and CSI ribbons are ESD-sensitive: handle with the system unpowered.
Legal note (Germany/EU)
If you operate this beyond a private bench — in a workshop with employees, in teaching with students — the Machinery Regulation and the employer's risk assessment apply to your installation. This guide documents our bench; it is not a conformity assessment.
Checkpoint: emergency stop tested with the belt running; arm homed with your hand on the stop; all of the above read by everyone who will stand at the machine.