Sensor Basics: What is the difference between 'dark-on' & 'light-on' photoelectric sensor switching?

Trying to select a opto-sensor? Or maybe a photoelectric product finder is asking you if you want "dark-on" or "light-on" sensor logic. This simple choice can trip up both novice and experienced users of automation.

Today I cover the answer to the question "𝑾𝒉𝒂𝒕 𝒊𝒔 𝒕𝒉𝒆 𝒅𝒊𝒇𝒇𝒆𝒓𝒆𝒏𝒄𝒆 𝒃𝒆𝒕𝒘𝒆𝒆𝒏 '𝒅𝒂𝒓𝒌-𝒐𝒏' 𝒂𝒏𝒅 '𝒍𝒊𝒈𝒉𝒕-𝒐𝒏' 𝒑𝒉𝒐𝒕𝒐𝒆𝒍𝒆𝒄𝒕𝒓𝒊𝒄 𝒔𝒆𝒏𝒔𝒐𝒓 𝒔𝒘𝒊𝒕𝒄𝒉𝒊𝒏𝒈?"

It's fairly straight forward actually if you think about it in the right way. This is all from the perspective of the light receiver. Do you want the sensor to turn on when the receiver sees light? Or when the receiver stops seeing light?

💡 In a thru-beam sensor or a retro-reflective sensor you typically want 'dark-on' switching because when the object blocks the light, you want the sensor to turn on.
💡 With diffuse sensors you want 'light-on' switching because the object reflects light back to the receiver.

For more automation basics videos like this one, be sure to SUBSCRIBE and then check out this link to my basics playlist.
Automation Basics

#WillAutomate
#industrialautomation
#sensors
#factoryautomation
#sensor
#manufacturing
#automation
#photoelectricsensor
#optosensor
#manufacturingautomation
#robotics
#roboticautomation