I have a question concerning the line impedance of Can bus. Currently we are communicating from an ECM to a Cluster with CA protocol. Each ECM and Cluster has a 120 ohms resistance inside for the impedanc termination. We are communicating at 250 kbauds on a really short distance, like 1 or meters.
Sometimes we branch a laptop on the bus to make a diagnostic.
The question is: When nothing is branched in the diagnostic plug, do w have to branch a 120 ohms resistance or we can lets it free.
Second question: Does the nodes for the diagnostic plug have to be exactl at the same distance on the bus, or one (CAN_H) can be closer of the EC and CAN_L closer of the cluster