What is the function of a CAN transceiver in an NMEA 2000 device?

• A. The transceiver handles power supply regulation.
• B. The transceiver converts CAN protocol signals to and from the device’s logic levels.
• C. The transceiver stores PGNs in flash memory.
• D. The transceiver encrypts the data traffic.

Answer: (B)

In NMEA 2000, the CAN transceiver is the interface between the device’s CAN controller and the CAN bus. It takes the controller’s digital TX signal and drives the two-wire bus with the proper CAN differential voltages (CAN High and CAN Low), and it also converts the incoming differential bus signals back into a logic-level signal the controller can process. This enables the device to participate in the bus’s arbitration and broadcast mechanism while providing electrical protection and ensuring the physical layer meets CAN specifications. The transceiver does not regulate power, store PGNs, or encrypt data; those functions are handled by other parts of the device.