NMEA 0183 and N2K


Broadly speaking NMEA comes in two different strains, the old NMEA 0183 (in various versions) and the more modern NMEA2000 (N2K). They are significantly different in the way they transmit data. However kit available to link the two makes the NMEA standard even more versatile and allows to stick to sensors already in place. There are various websites containing information for further reading on NMEA cabling and detals i.a. by Actisense.

NMEA 0183 shows pros and cons compared to NMEA2000 or dedicated systems like Seatalk made by Raymarine. What we appreciate with NMEA 0183 are now low prices for NMEA 0183 gear, second hand devices available eg on ebay, and robust systems’ performance which comes at the prize of more thinking required to set-up these types of systems. The latter has become even more relevant through very low-cost IT options using Arduino or Raspberry open standard computing platforms

Differences between NMEA 0183 & NMEA2000 (N2K)

NMEA 0183
N2K
Fully open/non-proprietory standard
Fully open/non-proprietory standard
One-way communication
Bi-directional
Open to other systems like NK2 and proprietary systems via adapter
Open to other systems like NMEA 0183 and proprietary systems via adapter
If one component/device fails, the others continue to work
If the bus fails there is a good chance the Nav system may come down completely
Relatively slow
Fast
Serial system, to be monitored with simple terminal program
CAN-Bus-type system, monitor with dedicated software
More complex to set-up, one-to-one cableing necessary
Plug & Play technology, one bus cable
Some compatibility issue between
versions RS 232 and RS422 equivalent

Cheap & 2nd hand units available
Pay market prices
Little future development to be expected to include more devices
Continuous inclusion of more equipment under way like engine controls

N2K is continuously expanded to include more devices like eg engine controls. Analogue/digital converters are available to include engine data like pressures, temperatures, tachymetre data, with non-specific kit available for virtually all analogue data to be converted. This is not to argue, that this is regarded a positive development for vessels putting to sea relying entirely on computerized displays.
Move on to who’s ‚talking‘ on board electronically