Shielding principle and function of J1939 to RP1226 cable

Shielding principle and function of J1939 to RP1226 cable

Shielding effect

Anti external interference: It can effectively block the interference of external electromagnetic signals on the transmission signals inside the cable. In industrial environments or automotive interiors where there are a large number of electromagnetic devices, it is possible to prevent electromagnetic radiation generated by nearby motors, spark plugs, and other equipment from entering the cable, avoiding interference with the data transmitted between J1939 and RP1226 interfaces, and ensuring the accuracy and completeness of signal transmission.

Preventing internal signal leakage: preventing the signal transmitted inside the cable from radiating outward, avoiding interference with other electronic devices around, ensuring that the signal is only transmitted inside the cable, improving the confidentiality and stability of signal transmission, and reducing the impact on other sensitive devices in the same environment.

Shielding principle

Reflection: The shielding layer is usually made of metal materials such as copper, aluminum, etc., which have good conductivity and magnetic properties. When external electromagnetic signals are incident on the shielding layer, some of the electromagnetic energy will be reflected back by the metal surface, thereby reducing the intensity of interference signals entering the interior of the cable.

Absorption: The metal shielding layer can absorb a portion of electromagnetic energy and convert it into other forms of energy such as heat energy, which can be consumed. This is because when electromagnetic signals propagate in metal, induced currents are generated inside the metal, which generate a magnetic field opposite to the original electromagnetic signal, thereby canceling out some of the electromagnetic energy.

Skin effect: For high-frequency electromagnetic signals, current will be concentrated near the surface of the conductor for transmission, and this phenomenon is called skin effect. The shielding layer utilizes the skin effect, allowing external interference signals to mainly propagate on the surface of the shielding layer and not penetrate deep into the interior of the cable, while also limiting the leakage of internal signals.