Why are terminators used on an NMEA 2000 CAN bus and where should they be placed?

Why are terminators used on an NMEA 2000 CAN bus and where should they be placed?

• A. They amplify the signal for longer distances and should be placed near the power supply.
• B. They prevent signal reflections and require placement at the two ends of the trunk.
• C. They are optional on NMEA 2000 networks.
• D. They provide power to devices.

Answer: (B)

On a CAN-based NMEA 2000 network, the signal is carried along a trunk line that can be tapped by many drop cables. To prevent reflections that distort data, the line must be matched to its characteristic impedance. That’s done with terminators at the two physical ends of the trunk. These terminators are passive 120-ohm resistors that absorb the signal as it reaches the ends, keeping the electrical characteristics stable for reliable communication. They don’t provide power or amplify the signal. Placing them at the ends, rather than in the middle or at the power supply, is essential for proper operation.

On a CAN-based NMEA 2000 network, the signal is carried along a trunk line that can be tapped by many drop cables. To prevent reflections that distort data, the line must be matched to its characteristic impedance. That’s done with terminators at the two physical ends of the trunk. These terminators are passive 120-ohm resistors that absorb the signal as it reaches the ends, keeping the electrical characteristics stable for reliable communication. They don’t provide power or amplify the signal. Placing them at the ends, rather than in the middle or at the power supply, is essential for proper operation.