NMEA 0183

NMEA 0183
Name	NMEA 0183
Developer	National Marine Electronics Association
Introduced	1983
Superseded by	NMEA 2000

NMEA 0183. NMEA 0183 is a marine serial communication protocol created for navigation and marine electronics interoperability. It defines electrical signaling, sentence structures, and data fields to transmit GPS, sonar, autopilot, and weather information among devices from vendors such as Garmin, Raymarine, Furuno, and Simrad. The standard enabled integration across systems used on vessels from shipyards like BAE Systems and Austal to recreational fleets from Carnival Corporation and Royal Caribbean.

Overview

NMEA 0183 specifies data exchange for instruments including Global Positioning System, Inertial navigation system, Radar (radio detection and ranging), Echo sounding, Automatic Identification System, and Anemometer outputs. Implementations by companies such as Garmin, Raymarine, Furuno and Simrad provided interoperability with chartplotters and multifunction displays from Lowrance, Humminbird, B&G (company), and Navico. The protocol influenced marine electronics standards organizations including the International Maritime Organization, International Electrotechnical Commission, and trade groups like the National Marine Electronics Association.

History and Development

Originating in the early 1980s, the standard emerged amid evolving marine electronics from firms such as Magellan (navigation) and Trimble Inc. to meet needs similar to those driving standards in aerospace by Garrett AiResearch and telecommunications by AT&T. Early adoption by chartplotter manufacturers paralleled navigation advances from the United States Coast Guard and mapping work at the Ordnance Survey. Revisions reflected input from marine OEMs including Siemens, Honeywell, and Schneider Electric as recreational and commercial shipping sectors—represented by companies like Norwegian Cruise Line and Maersk—required reliable sensor networks.

Protocol and Message Structure

NMEA 0183 uses ASCII characters with sentences beginning with a dollar sign and ending with carriage return/line feed, encoding fields separated by commas. Messages carry identifiers that reference talker devices such as GPS receivers from Garmin or Trimble, heading sensors by Fluxgate compass makers, and depth sounders by Kongsberg Maritime. The checksum uses XOR over payload bytes, analogous to error detection in protocols from Cisco Systems and IBM networking equipment. The architecture resembles serial interfaces standardized by EIA and adopted in equipment by Motorola and Texas Instruments.

Sentence Types and Examples

Common sentence types include GGA, GLL, RMC, VTG, and GSA, used by receivers from Furuno and Garmin to report fix, position, velocity, and satellite data. Example sentences demonstrate fields for UTC time, latitude/longitude, fix quality, and number of satellites—data relevant to services such as NOAA weather integrations and mapping by Esri. Manufacturers like Raytheon Technologies and Lockheed Martin used NMEA 0183 outputs in marine avionics testbeds. Example: a GGA sentence conveys time, position, and fix status similar to reports produced for United States Geological Survey instrumentation.

Physical and Electrical Interface

Electrically, NMEA 0183 initially specified current-loop and later RS-232 or RS-422/RS-485 compatible signaling implemented by hardware suppliers including National Semiconductor, Maxim Integrated, and Analog Devices. Wiring conventions allow single-ended and differential links used in installations by shipbuilders like Meyer Werft and Fincantieri. Connectors from vendors such as Amphenol and TE Connectivity are common in harnesses alongside power distribution by ABB and Schneider Electric. The standard’s serial framing paralleled industry practices in telecommunications by Bell Labs and industrial automation by Rockwell Automation.

Implementation and Interoperability

Equipment manufacturers implemented NMEA 0183 across chartplotters, autopilots, and sensors; integration challenges prompted middleware solutions from companies like Actisense and software stacks in projects by OpenCPN and Signal K. Interoperability testing involved labs affiliated with Det Norske Veritas (now DNV) and compliance programs run by the National Marine Electronics Association. Marine software such as MaxSea and Navionics consumed NMEA streams for charting and route planning used by commercial operators including MSC Cruises and scientific teams from Scripps Institution of Oceanography.

Limitations and Successors

Limitations include single-sender/talker constraints, low bandwidth, and lack of standardized multiplexing, prompting migration to NMEA 2000 and industry protocols inspired by Controller Area Network developed by Bosch. NMEA 2000 adoption by major vendors like Garmin and Raymarine addressed many scalability and networking limitations, while marine Ethernet solutions from Hewlett-Packard Enterprise and Cisco Systems provide higher throughput for integrated systems aboard vessels from Carnival Corporation to naval platforms built by BAE Systems.

Category:Marine electronics