The backbone of an NMEA 2000 network is typically made of what type of cable?

• A. Light-weight wire
• B. Fiber optic
• C. Coaxial cable
• D. Heavy Cable

Answer: (D)

The backbone is the main trunk that carries both the CAN data and the power needed by multiple devices along the network. It needs to be a robust, low-resistance copper two-conductor cable, chosen in a heavier gauge so voltage drop along long runs is minimized and enough current can be supplied to devices without sagging voltage. That reliability is essential on a boat where devices can be spread far apart and the environment is harsh. Fiber optic wouldn’t carry the CAN electrical signal natively, coaxial cable isn’t arranged as the required two-wire CAN trunk, and light-weight wire wouldn’t withstand the power delivery and conditions aboard a vessel. So a heavy cable is used for the backbone.