Table of Contents
Electrical Power Supply Requirements
NMEA 2000
I don't have the standard. The following is assembled from credible looking sources on the web.
Bus power supply standard from 9V - 16V. Presumably that is just a wide nominal 12V, rather than people actually choosing to use 9V.
Load Equivalency Number (LEN) - This seems to mean a 50mA draw from the CAN bus power lines.
It will supply up to 3A total.
Voltage drop must be <1.5V over whole network, to keep the data link happy.
Three different cable sizes are standard. The smallest one is common on boats.
“Lite” cable: 22 AWG power, 24 AWG data. “Micro” connector. 57 mOhm per m.
Connectors
Physical layer of NMEA2000 is based on (same as?) DeviceNet.
Micro is M12. 5 pin, one in centre. Mini is bigger and has different pin layout with one at top. “A coded”.
- Male on device.
- Cables are male to female.
- T-connectors (3 way junction) have M and F on the ends, F in middle to connect to device with M-F cable.
- SeaTalkNG is same as NMEA 2000 but with a different connector.