CAN repeaters are used to establish the physical and logical coupling of two or more segments of a CAN bus system. Depending on the model, tree or star topologies or even long stub lines can be realised. The maximum number of bus nodes can also be increased. Optically isolated CAN repeaters separate and protect critical segments of the system from the rest of the CAN network. Galvanic protection isolates both CAN segments from each other as well as from the power supply.