Have you ever wondered what DARK-ON and LIGHT-ON actually mean when it comes to photoelectric sensors?

For LIGHT-ON operation when the receiver 'sees' the light source it will indicate an active or detected indication. If the light source is blocked this sensor will be inactive. 

For DARK-ON operation it's basically the opposite. The sensor will be inactive as long as it can see the emitting light source. If the light source is blocked this sensor will be active, thus the name DARK-ON (when the light is 'dark' the sensor is 'on').

Another way of saying it would be if you need an output when no light is received you need DARK-ON. If you need the output on while the receiver is receving light you would need LIGHT-ON.

Marshall Wolf Automation is your authorized stocking distributor for all the top brands of photoelectric light sensors including Autonics, Baumer Electric, Carlo Gavazzi sensors, Datasensor, IDEC, Leuze, Pepperl+Fuchs, Takex and Visolux.

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