The beacons are mounted above the guard in a position visible to the operator, who may some distance away at the time they check them. They offer a clear signal to confirm that the machine is ready for operator to enter and perform the next load/unload task, or whether they should wait in the case where the machine is yet to complete its work.
The signal beacons shows the operator at what stage the machine is. It gives the operator simple and clear instruction. It will identify if at any time there is a fault such as not making an appropriate sensor.
These are usually fitted to a pallet inverter or exchanger with automatic controls and in some cases combined with remote control.