How does a PLC Control Photoelectric Sensor?

A photoelectric sensor is a device that converts optical signals into electrical signals. Its working principle is based on the photoelectric effect. The photoelectric effect refers to the phenomenon of the corresponding electrical effect occurring when the electrons of the material absorb the energy of photons when light is irradiated on certain substances. Photoelectric switch is generally used for automation equipment. This blog mainly introduces how does a PLC control photoelectric sensor.

This is ATO photoelectric sensor.

We will connect the photoelectric sensor output to the PLC input. Because we use the drain transistor PLC (input 0V signal, output 24V+), so we choose the photoelectric sensor to be NPN type.

The photoelectric sensor output is defined as 0.03 of PLC.
The PLC output 101.02 is defined as the coil input of the intermediate relay.
The PLC program is compiled without errors.

The brown and blue of the sensor are connected to 24V+ (+) and 0V (-) respectively.
The black output wire of the sensor is connected to the PLC input 0.03.
The negative pole of the coil of the intermediate relay is connected to the output terminal 101.02 of the PLC.
The positive pole of the coil is connected to 24V+.

At this time we can observe that the indicators of 0.03, 101.02 and relay KA are not on.

When the light from the photoelectric sensor is blocked,
The indicator lights of 0.03, 101.02 and relay KA are all on.

Using this principle, we can use the relay KA to control higher voltages or other components.

If you want to know more about how to connect photoelectric sensor with PLC, please view the video below. What’s more, ATO.com provides through beam photoelectric sensor, diffuse reflective photoelectric sensor, retro-reflective photoelectric sensor and slot type photoelectric sensor for you, high performance and low cost. Shop online now!