Pepperl+fuchs Phototalk

A photoelectric sensor uses an oscillator to modulate its light source.  The modulated light source transmits infrared or visible red light.  The light is returned or reflected back to the sensor and is detected by the receiver.  If the returned light is above a certain threshold, the sensor’s output changes states.  The output of a 4-in-1 sensor can be either: --PNP light on --PNP dark on --NPN light on --NPN dark on