M12 Circular Connector 4 Pin Definition

As a core component in the field of industrial automation, M12 connectors are widely used in sensor connection, industrial network communication and data transmission. Among them, the 4-pin M12 connector is ideal for many electrical connection needs due to its compact structure and reliable performance. Understanding its wiring diagram and function definition is essential to ensure the correct installation and efficient operation of the equipment.

Overview of the M12 Connector 4-pin interface

The M12 connector 4-pin interface is designed in a standard circular layout with pin spacing calculated to ensure electrical insulation and mechanical stability. Enclosures are usually made of metal or high-strength engineering plastics with good protective properties (such as IP67 or higher) to adapt to complex and changeable industrial environments.

Standard connection definition

According to the international general industry standard, the 4-pin wiring of the M12 connector is defined as follows:

Pin Number	Function Definition	Typical Application
1	Positive Power (V+)	Provides the positive voltage required by the device, typically ranging from 12V to 24V depending on specific application needs.
2	Signal Transmission Line (S)	Responsible for transmitting data collected by sensors or control signals, serving as the core line for data exchange.
3	Signal Return Line (S-) or Ground (GND)	Forms a complete signal loop with Pin 2 and can also serve as system grounding, providing a stable electrical reference point.
4	Negative Power (V-)	Form a power supply circuit with pin 1 to ensure the normal flow of current inside the device and supply power to each function module.

Wiring Diagram Example

Diagram Explanation:

The circular part represents the main body of the M12 connector.

Four wires extend from the edges of the circle, labeled with corresponding pin numbers and functions:

Pin 1: V+

Pin 2: S

Pin 3: S-/GND

Pin 4: V-

In actual wiring, appropriate wire specifications should be selected based on current size and transmission distance. Wires should have good temperature resistance, wear resistance, and oil resistance to meet the harsh requirements of industrial environments. Connection methods can include soldering, crimping, or using dedicated terminals to ensure reliable electrical connections.

Wiring Variations in Special Applications

In certain specialized industrial scenarios, the function allocation of the M12 connector's 4-pin configuration may be adjusted according to specific needs. Below are some typical application cases:

Daisy Chain Connection

In distributed sensor networks, pin functions can be reassigned to enable daisy chain connections, supporting address encoding information or control signal transmission.

High Electromagnetic Interference Environment

In environments requiring high electromagnetic compatibility, a shielding layer can be added and connected to the appropriate pin or housing to further enhance the system's interference resistance.

Wiring Precautions

To ensure the safety and reliability of M12 connector 4-pin wiring, the following precautions must be observed during operation:

Power Off Operation

Ensure the equipment is completely powered off before wiring to avoid electric shock hazards or damage caused by improper operation.

Verify Wiring Diagram

Carefully check the wiring diagram against the actual equipment requirements to prevent wiring errors that could cause the equipment to malfunction or lead to accidents.

Ensure Connection Quality

Solder joints should be smooth without voids to ensure conductivity.

Crimp terminals must fit tightly, conforming to relevant electrical connection standards.

Protective Treatment

For applications in harsh environments, appropriate protective measures should be taken for the connection points, such as using sealant or heat shrink tubing, to prevent moisture, dust, and oil from entering the connector and affecting its electrical performance and service life.

Conclusion

The M12 connector 4-pin wiring diagram is key to understanding and applying this type of connector. By mastering its standard wiring definitions, familiarizing yourself with functional adjustments in special application scenarios, and strictly adhering to wiring standards, the stable operation and efficient work of the entire electrical system can be effectively guaranteed.

Whether you are a device manufacturer, system integrator, or maintenance engineer, a deep understanding of the M12 connector 4-pin wiring knowledge is an indispensable professional skill. As industrial automation continues to evolve, the M12 connector will play an increasingly important role in more fields.

If you require further technical support or customized solutions, please contact Connoder, a professional connector supplier. Our team of engineers will provide comprehensive services and support tailored to your needs.