- (1.2.3): Disconnect the sensor and insert the box in the correct direction (male-female or female-male). This box has 4-pin M12 connectors.
- (4) With a voltmeter, check the power supply to the sensor on terminals 1 & 3.
- (5,6): Put a piece to be detected and check the voltage change on terminal 4 & 1 for a NPN sensor or between terminal 4 & 3 for a PNP sensor.
-(7,8): Put a piece to be detected and check the voltage change terminal 2 & 1 for a NPN sensor or between terminal 2 & 3 for a PNP sensor.
To note: Often, sensors have a light diode that activates when they detect. Be careful that this diode does not validate the sensor check. The diode may be defect and the sensor may be working fine or the diode may be working and the sensor may be fault.