Safety Light curtains are electro sensitive devices using one or more light beams, emitted by an Emitter and received by a Receiver, to create an intangible controlled area.
Safety type:- Defines the self-monitoring and safety principles contained in the device; it must be chosen as a function of the risk level characterising the machine.

Protected height:- This is the height controlled by the light curtain. If it is positioned horizontally, this value shows the depth of the protected zone.
Range:-This is the maximum working distance that may exist between the emitter and the receiver. When deflection mirrors are used, it is necessary to take into account the attenuation factor introduced by each of them, which it is about 15%.
Response time:-This is the time it takes for the light curtain to transmit the alarm signal from the time the protected zone is interrupted.
Resolution:- The resolution of a light curtain is the minimum size of an object that, placed into the controlled area, will obscure the controlled zone and hence stop the hazardous movement of the machine.