Which value is associated with the mid cable's data wire gauge?

• A. 22 awg
• B. 20 awg
• C. 18 awg
• D. 16 awg

Answer: (B)

In NMEA 2000 networks, the data pair that carries the CAN signals on spur cables is sized to balance signal integrity with flexibility and cost. The mid cable’s data wire is specified as 20 AWG because this gauge provides enough conductance to keep the CAN signal within acceptable voltage drop and noise margins over typical spur lengths, while remaining easy to route and cost-effective. Using a thinner wire, like 22 AWG, would increase resistance and could degrade signal quality on longer spurs. Using a thicker wire, such as 18 or 16 AWG, would unnecessarily add stiffness and cost since the data pair only carries a low-current CAN signal, not power. So 20 AWG is the appropriate compromise for the mid cable’s data wire.