Electronic – CAN bus connector issue


I've got a circuit with a CAN bus connector like the following with two RJ11 connectors to be connected in a daisy-chain style:


But only one of them is working (I tested them by connecting to another terminal node with a single connector). The soldering is correct.

When I measured the resistance between CANH and CANL with a jumper on each end, the working connector resistance was 60 ohms as expected, but'll be 120 ohms when connected to the not-working connector or with both connected. What'll be the problem in this case?

Best Answer

It's not possible to find your bug remotely. The schematic is correct.

However you already found out that one of the connectors is not working. One or both CAN signal lines seem to be broken. Are you sure the soldering is really OK? And are the contacts clean and in a good shape?

You should also measure the resistance of one of the signal lines between certain points, e.g. between somewhere on the PCB and the contact inside the connector. Also, your cable to connect the next node may be broken.