M12 4-Pin Pinout Diagram for Sensor and Industrial Wiring
4-pin circular connector
Standards: IEC 61076-2-101, DIN EN 61076-2-101
What is the M12 4-Pin pinout?
The M12 4-Pin Industrial Connector has 4 pins. Pin 1 is +V (power). Pin 2 is OUT (data). Pin 3 is GND (ground). Pin 4 is IN (data).
Standards: IEC 61076-2-101, DIN EN 61076-2-101
Pin Assignment Table
| Pin | Signal | Type | Description |
|---|---|---|---|
| 1 | +V | power | Power Supply (+24V DC typical) - Brown wire |
| 2 | OUT | data | Signal Output - White wire |
| 3 | GND | ground | Ground (0V) - Blue wire |
| 4 | IN | data | Signal Input - Black wire |
Signal Types
Common Applications
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Use this connector in the release workflow →The M12 4-Pin connector has 4 pins: Pin 1 (+V, 24V), Pin 2 (OUT), Pin 3 (GND), and Pin 4 (IN). Common in Industrial sensors and Actuators.
M12 A-Coded Pinout (4-Pin)
The M12 connector is the backbone of industrial automation and Industry 4.0. The 4-pin A-coded variant is the most common configuration, used for DC-powered sensors (proximity, inductive, photoelectric) and actuators. The A-coding refers to the specific keyway that prevents mating with other M12 variants like D-coded (Ethernet) or B-coded (Fieldbus).
Wiring Tips & Best Practices
M12 connectors come in male (plug) and female (socket) variants with mirrored pin numbering. Always identify if you are viewing the front face (mating side) or rear (solder side). Standard wire colors: Brown = +V (Pin 1), White = Signal Out (Pin 2), Blue = Ground (Pin 3), Black = Signal In (Pin 4). For NPN sensors, the output switches to ground; for PNP sensors, the output switches to +V. Most modern PLCs accept both types.
Common Issues
Mixing up male/female pin orientation causes wiring errors - always verify which end you are viewing. Over-tightening the locking nut can damage the seal (torque to 0.6-0.8 Nm). Using static-rated cables in drag chain applications leads to premature failure. Ensure IP67 rating is maintained by using properly torqued connections and undamaged seals.
Why Use Interactive Diagrams?
- Accuracy: Hover over pins to see exact signal names and descriptions
- Clarity: Color-coded by signal type (power, ground, data)
- Printable: Export clean diagrams for shop floor reference
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Next Steps
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