A 3-wire Autonics Proximity Sensor is used to detect the presence of an object without physical contact and send a clean signal to a controller such as a PLC. It has three wires — power (V+), ground (0V), and output. This separate output line allows better stability, faster switching, and accurate response compared to a 2-wire sensor, which combines power and signal in the same line. The 3-wire configuration ensures consistent operation and reduced electrical noise in automation systems.
In an inductive sensor, the circuit produces a high-frequency electromagnetic field at the sensing face. When a metal object enters this field, the oscillation weakens, and the detection circuit identifies the change, switching the output signal. In capacitive sensors, the sensor detects changes in capacitance when materials like plastic, glass, or liquid approach the sensing area.
When a target object is detected, the sensor’s output (PNP or NPN) changes state, sending a clear ON/OFF signal to the control system. The 3-wire design delivers high accuracy, quick response, and strong noise immunity, making it ideal for precise detection in modern industrial automation and machinery control applications.