AOTORO EK51-T20M4 (01) PDF Document

The model number provides details about the switch’s features:

EK: Photoelectric switch, Relay contact output type

51: Serial number / side length

T: Detecting method – Through-beam

20: Detecting distance – 20m

M: Control output – Free power relay output

4: Function – Light ON/Dark ON switch selectable

The operation mode can be selected using a switch on the device.

Light ON Mode:

In this mode, the TR output turns ON when the receiver receives light from the emitter. The output turns OFF when the light is interrupted by an object.

Dark ON Mode:

In this mode, the TR output turns ON when the light from the emitter is interrupted by an object. The output turns OFF when the receiver is receiving light.

The AOTORO EK51-T20M4 is a through-beam type sensor, which consists of an Emitter and a Receiver.

Emitter (Transmitter) Wiring:

This unit has two wires for power.

Brown: Connect to Power (24-240V AC/DC)

Blue: Connect to Power (24-240V AC/DC)

Receiver Wiring (Free power relay output):

This unit has five wires for power and the relay output.

Brown: Connect to Power (24-240V AC/DC)

Blue: Connect to Power (24-240V AC/DC)

White: Relay COM (Common)

Black: Relay N.O (Normally Open)

Gray: Relay N.C (Normally Closed)

Follow these steps for installation and adjustment:

1. Install the emitter and the receiver facing each other, then supply power to the photoelectric sensor.

2. Adjust the receiver and the emitter right/left and up/down. Set the receiver in the center of the position where the operation indicator turns on.

3. Fix both units tightly after checking that the units detect the target.

Follow these steps for installation and sensitivity adjustment:

1. Supply power to the photoelectric sensor after setting the photoelectric sensor and the mirror (reflector) to face each other.

2. Set the photoelectric sensor in the position where the indicator turns on by adjusting the mirror or the sensor right/left and up/down.

3. Fix both units tightly after checking that the unit detects the target.

Note: If using more than 2 photoelectric sensors in parallel, the space between them should be more than 30cm.

Note: Sensitivity adjustment for this type is the same as the diffuse reflective type.

Follow these steps for installation and sensitivity adjustment:

1. The sensitivity of the sensor must be adjusted in accordance with the existence of any reflective material in the background, even when the sensor is set to its maximum sensitive position.

2. Place the target in the detecting area. Turn the sensitivity adjuster from the MIN position until the indicator just turns ON. Note this position.

3. Remove the target from the sensing area. Then, turn the adjuster from the position noted in step 2 towards MAX until the indicator turns ON. If the indicator does not turn on, the MAX position is the second point. Note this position.

4. Set the adjuster to the center point between the two positions noted in steps 2 and 3 for the optimal setting.

Note: If the reflectance of a target is higher than non-glossy white paper, it might cause a malfunction due to reflection when the target is near the photoelectric sensor. To prevent this, ensure there is enough space between the target and the sensor, or install the target’s surface at an angle of 30 to 45 degrees relative to the optical axis.

Be sure to follow the safety precautions below for added safety:

1. Do not use the sensor in an environment with explosive or flammable gas.

2. Never disassemble, repair, or tamper with the product.

3. Keep the supply voltage within the specified area.

4. Use the load under the specified area.

1. Environmental Conditions:

Do not use the product under the following conditions:

(1) In a place with direct sunlight.

(2) In a place where humidity is high and condensation may occur.

(3) In a place where corrosive gas exists.

(4) In a place where vibration or shock is directly transmitted to the product.

2. Connection and Mounting:

(1) Before connecting power, ensure the supply voltage is less than the maximum rated supply voltage.

(2) If the photoelectric switch cable must be laid in a conduit with a high-tension or power line, it can cause induction, possibly resulting in malfunction or damage. In principle, the cable should be laid separately or shielded.

(3) For extending wires, use a cable with a cross-section greater than 0.3mm² and a length of less than 100m.

(4) Do not pull the wire with strong force.

(5) Do not apply excessive force (such as hitting with a hammer) to the sensors, as it may damage their water resistance.

3. Power Supply:

When using a commercially available switching regulator, be sure to ground the FG (Frame Ground) terminals.

4. Power Supply Reset Time:

The photoelectric switch will begin sensing no later than 100ms after the power is turned on. If the load and the photoelectric switch are connected to different power supplies, the photoelectric switch must always be turned on first.

5. Turning Off Power Supply:

When turning off the power, an output pulse may be generated. It is recommended to turn off the power supply of the load or load line first.