What is the electrical performance of J1939 cable

What is the electrical performance of J1939 cable

The excellent electrical performance of J1939 cable is mainly reflected in the following aspects:

Strong anti-interference ability

The J1939 protocol requires the use of shielded twisted pair cables as the physical medium, effectively suppressing external electromagnetic interference (EMI) through differential signal transmission (CAN-H and CAN-L) and shielding layer grounding design. This structure can reduce signal attenuation and noise coupling, ensuring the stability of data transmission, especially in complex electromagnetic environments such as heavy vehicles and construction machinery.

Stable transmission rate

Based on the CAN 2.0B protocol, the transmission rate of J1939 cable is fixed at 250 kbps and supports real-time data exchange. The physical layer specification explicitly requires the use of cables with a characteristic impedance of 120 Ω and matching terminal resistors to eliminate signal reflections and maintain stable transmission rates.

Strict electrical interface specifications

Voltage range: The voltage range of each line of the interface cable conforms to the electrical characteristics specified in the protocol, ensuring accurate identification of signal levels.

Pin function: In a typical 9-pin layout, CAN-H、CAN-L、 The CAN Shield and other pins have clear division of labor, providing power (+12V), grounding, and signal transmission functions to avoid electrical conflicts.

Mechanical characteristics: The connector is designed to be sturdy, adaptable to vehicle vibrations and harsh environments, ensuring long-term electrical connection reliability.

Compatibility and Scalability

The electrical performance of J1939 cable is highly compatible with CAN controllers, supporting the encapsulation of multiple frames of data through Protocol Data Units (PDUs) to achieve flexible transmission of Parameter Groups (PGNs). In addition, its physical layer specification allows for dynamic address allocation, providing expansion space for new devices.