What is the network interface of industrial robots like

What are the network interface types for industrial robots?
Two main types of network interfaces for industrial robots  （ distinction + usage)
The network interfaces of industrial robots are divided into only two categories: fixed industrial RJ45 network ports for control cabinets and M12 circular industrial Ethernet aviation interfaces for robot arms. These two have completely different appearances， structures， and application scenarios.

1. Control cabinet panel： Industrial reinforced RJ45 network port (most common debugging port)
Appearance
It is a rectangular 8-pin network port (similar to the shape of computer and router network ports)， but it belongs to an industrial shielded model：
Metal fully enclosed shielded housing， 8 gold-plated contacts inside， and usually a link / status indicator light (yellow and green LEDs) beside the interface；
High-end robot control cabinets have RJ45 ports with side screw locks， which are tightened and fixed after plugging in the network cable， preventing vibration loosening， different from the plastic snap fasteners used in home appliances；
Protection level IP20， only used inside the control cabinet / the inner side of the cabinet door， not directly exposed to oil stains， water spray environments.
Location and function
Installation location： robot control cabinet door， industrial control motherboard， switch panel；
Usage： direct connection for computers， debugging， program upload and download， connection to PLC， upper computer， MES， industrial switch networking；
Compatible cables： industrial shielded network cables (green / purple Profinet/EtherCAT dedicated network cables， with shielded crimp terminals).
2. Robot arm body： M12 circular Ethernet interface (main for movement parts)
Overall appearance
Circular threaded aviation plug， outer diameter 12mm， tightened and locked by a threaded nut， waterproof， dustproof， shock-resistant (IP67)， is a standard network interface for robot arms， servo motors， and industrial cameras.
M12 to RJ45 industrial network cable
Two codes (cannot be mixed， key distinction)
M12 D code (4 pins)
Rate： 100M， compatible with EtherCAT， Profinet motion buses；
Scenario： robot joint servo drive， control cabinet to robot arm main communication line.
M12 X code (8 pins)
Rate： Gigabit / 10 Gigabit， large bandwidth；
Scenario： robot 3D vision camera， high-speed image transmission main wiring.
M12 circular female interface Core advantage
The mechanical hand keeps swinging and bending, causing significant vibrations in the workshop. Ordinary RJ45 plastic snap connectors would loosen the wires when shaken, but the M12 threaded fasteners will not loosen at all after being tightened, and they can also prevent the splashing of cutting fluid and dust. 
III. Comparison Table of Two Interface Core Components Table
Features: Industrial RJ45 network port, M12 circular Ethernet interface
Appearance: Rectangular crystal socket, circular threaded aviation plug
Locking method: Plastic snap-on / side screw fixation, metal threaded tightening
Protection level: IP20 (dry environment inside the cabinet) / IP67 (waterproof, oilproof, dustproof)
Installation location: Inside the robot control cabinet / Cabinet door, mechanical arm body, servo motor, vision camera
Common bandwidth: Gigabit, D code 100 Mbps / X code 1000 Mbps
Typical applications: Equipment debugging, production line networking, upper computer communication, main body motion control bus, mobile part communication
Four. Supplementary: Conversion form
In the field, M12 male connectors are often used to convert to RJ45 crystal head finished network cables. One end is plugged into the M12 port of the robot arm, and the other end is plugged into the RJ45 port of the control cabinet switch to complete the entire line communication connection.
Five. Quick identification tips
When opening the robot control cabinet, seeing the rectangular network port = industrial RJ45 debugging port;
Following the mechanical arm's wiring path, seeing the circular threaded connector = M12 industrial Ethernet network interface;
Most purple outer skin network cables are Profinet, and green outer skin cables are mostly EtherCAT industrial Ethernet cables.