In a J 1939 CAN Bus, what is the expected resistance in a CAN Transceiver Resistance test?

In a J1939 CAN Bus system, the expected resistance in a CAN Transceiver Resistance test is typically 120 Ohms. This specification is crucial because it defines the characteristic impedance of the CAN Bus, which is designed to ensure that signals propagate effectively along the network without significant reflections that could lead to data errors.

Both ends of the CAN Bus are terminated with a 120 Ohm resistor to match this impedance. This termination helps to minimize signal reflection and maintains signal integrity across the network, thereby allowing multiple nodes to communicate effectively.

The option stating 60 Ohms is likely related to other types of systems or cabling, while 30 Ohms and 100 Ohms do not align with standard CAN Bus specifications. It’s critical for technicians and engineers working with J1939 systems to understand these resistance values for troubleshooting and ensuring proper system operation.