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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 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.