How to determine the quality of J1939 to J1708 cable?

How to determine the quality of J1939 to J1708 cable?

To determine the quality of the J1939 to J1708 cable, the following aspects can be considered:

Appearance inspection

Cable sheath: The sheath of high-quality cables should be smooth, without obvious defects, bubbles or cracks, with uniform texture and a certain degree of flexibility, and not easily torn. The markings on the outer skin are clear and complete, including cable specifications, models, manufacturers, and other information.

Connector: The surface of the connector should be flat, free of burrs, deformation, and the metal parts should be free of rust, oxidation, and other phenomena. The fit between the plug and socket should be tight, smoothly inserted and removed, without any looseness or jamming sensation. Observing the pins of the connector, they should be arranged neatly, without bending, breaking or corrosion. The coating of the pins should be uniform and smooth to ensure good conductivity.

Shielding layer: Check whether the shielding layer of the cable is intact, whether there is any damage, breakage or exposure. The shielding layer of high-quality cables is usually made of materials such as metal woven mesh or aluminum foil, which can effectively block external electromagnetic interference.

Electrical performance testing

Conductivity: Use the resistance range of a multimeter to measure the resistance between the corresponding pins at both ends of the cable. Under normal circumstances, the resistance value should be very small, close to zero, indicating good conductivity of the circuit. If the resistance value is too high or infinite, it indicates that there may be an open circuit fault inside the cable.

Insulation performance: Use an insulation resistance tester to measure the insulation resistance between each core wire of the cable and between the core wire and the shielding layer. Generally speaking, the insulation resistance should be above the megaohm level, and the higher the insulation resistance value, the better the insulation performance of the cable. If the insulation resistance value is too low, there may be problems such as insulation layer damage or moisture.

Signal transmission: Professional communication testing equipment such as CAN bus analyzers can be used to perform signal transmission testing on cables. Send specific J1939 and J1708 protocol signals to one end of the cable, and receive and analyze the integrity, accuracy, and transmission rate of the signals at the other end. High quality cables should be able to accurately transmit signals without obvious distortion, delay, or packet loss, and the transmission rate should comply with the provisions of J1939 and J1708 protocols.

Anti interference capability: Evaluate the anti-interference ability of cables through electromagnetic compatibility (EMC) testing. In a laboratory environment, place cables near sources of electromagnetic interference of a certain intensity, such as radio frequency electromagnetic fields, electrostatic discharge, etc., and observe the quality of the signals transmitted by the cables. High quality cables should be able to maintain normal signal transmission under a certain degree of electromagnetic interference, without data errors or communication interruptions.

Structural and Material Analysis

Cable structure: Cut a small section of the cable and observe its internal structure. The internal structure of high-quality cables should be clearly layered, with the core wires, insulation layers, shielding layers, etc. arranged neatly and tightly. Core wires are usually made by twisting multiple strands of copper wire, with uniform thickness and soft texture to increase the flexibility and conductivity of the cable.

Material quality: judged by the core wire and outer sheath material of the cable. The core wire material should be high-purity copper, and the higher the purity of copper, the better the conductivity. By observing the color and texture of the copper wire, a preliminary judgment can be made that high-quality copper wire should have a purple red color and a shiny texture. The outer skin material should have good wear resistance, corrosion resistance, and high temperature resistance.