Light curtains protect personnel from injury and machines from damage by creating light screen that guards access points and perimeters. If the screen is broken or blocked, any connected devices or machinery will shut off.
Light curtains work by sending several beams of light from a transmitter to a receiver. If any beams are interrupted, a signal is sent to the machine's control panel to turn off the machine. When the connection is reestablished, an automatic reset signal is sent to the control panel to resume operation.
Light curtains can be configured to detect fingers, hands, or whole body parts, based on increasing beam resolution. Blanking and muting are also possible, so the light curtain can permit entry of certain items (like boxes) and deny others (hands).