Why might you choose to add a repeater or isolator in an NMEA 2000 network?

• A. To convert NMEA 2000 to Ethernet.
• B. To increase PGN transmission rate.
• C. To extend trunk length, decrease electrical noise, and to reduce fault propagation; isolators help prevent ground loops.
• D. To reduce device count.

Answer: (C)

The main idea is that repeaters and isolators manage signal reach and fault tolerance on an NMEA 2000 network. A repeater regenerates and repeats the CAN signal, letting you place devices farther apart and effectively extend the trunk length beyond a single segment’s limit. An isolator provides galvanic isolation between segments, which reduces ground loops and prevents faults on one side from propagating to the rest, while also helping to cut down on noise coupling between parts of the network. Taken together, these devices improve reliability by extending reach, reducing electrical noise, and containing faults. They don’t convert NMEA 2000 to Ethernet, they don’t increase the PGN transmission rate, and they don’t reduce the number of devices on the network.