Pepperl+fuchs Phototalk

Rather than using the standard convention for describing the photoelectric sensor outputs as normally open (NO) or normally closed (NC), most photoelectric sensor manufacturers specify the output behavior as being either light ON or dark ON. In this episode, Michael and Helge discuss how the terms light ON and dark ON apply to photoelectric sensors. --Light ON (LO) means that the sensor’s output is ON when it receives light. --Dark ON (DO) means that the sensor’s output is ON when it is dark (i.e. receives no light).