CAN Copper to Fiber Converter Model CANFB Model CANFB isolates and protects your CAN (Control Area Network) system from component killing surges and transients in a noisy and harsh environment. The CANFB is a copper to fiber converter that provides optical isolation for the CAN system. This separates and protects critical segments of the system from the rest of the CAN network. It is protocol independent, allowing it to work with all the different CAN protocols and frame lengths. The Model CANFB converter is used in pairs, one for each side of the fiber.