NMEA 0183 is a combined electrical and data specification for communication between marine electronics, such as echo sounders, sonars, anemometers, gyrocompasses, autopilots, and GPS receivers. It has been slowly replaced by the newer NMEA 2000 standard, though it remains widely used for legacy system integration. Fundamental Data Structure The NMEA 0183 standard uses a simple ASCII serial communications protocol where data is transmitted in "sentences" from a single "talker" to one or more "listeners". Sentence Format : All standard sentences start with a $ character and end with a carriage return/line feed . Address Field : The first five characters following the $ indicate the talker ID (e.g., GP for Global Positioning System) and the sentence type (e.g., GGA for Fix Data). Data Fields : Commas are used to delimit data fields. If data is unavailable, the field is left blank between commas. Checksum : Most sentences include an optional checksum at the end, preceded by an asterisk * , to ensure data integrity during transmission. Common NMEA 0183 Sentences Description Key Data Provided $GPGGA Global Positioning System Fix Data Time, position, fix quality, and altitude. $GPGLL Geographic Position - Latitude/Longitude Latitude, longitude, and UTC time. $GPGSV GNSS Satellites in View Number of satellites, PRN numbers, elevation, and azimuth. $GPRMC Recommended Minimum Specific GNSS Data Time, date, position, speed, and course. $GPVTG Course Over Ground and Ground Speed Actual track made good and speed over ground. Hardware & Electrical Specifications Interface : Based on the RS-422 standard, utilizing two wires for transmitting (Talkers) and two for receiving (Listeners). Baud Rate : The standard speed is 4,800 bps , though some "High Speed" variations (used for AIS) operate at 38,400 bps. Transmission Distance : Supports cable lengths up to 100 meters at standard speeds. Reference Resources For technical implementations, you can consult detailed guides like the Everything you need to know about NMEA 0183 PDF from Actisense or the NMEA 0183 Information Sheet provided by UiB.
proprietary sentences for a specific brand like Raymarine or Furuno? AI can make mistakes, so double-check responses Copy Creating a public link... You can now share this thread with others Good response Bad response 10 sites The NMEA 0183 Information sheet | Actisense The NMEA 0183 standard slowly became the common method by which marine electronics devices could talk to one another. The standard... Actisense NMEA-0183 Messages Guide for AgGPS Receivers Association (NMEA) messages to transfer GPS position data between electronic equipment. Information on the NMEA-0183 communication... Elizabethtown College NMEA-0183 Sentences for GPS Receivers - Computer Science - JMU * 1 Introduction. The National Marine Electronics Association (NMEA) has a standard for the formatting of Global Positioning Syste... James Madison University NMEA 0183 - National Marine Electronics Association The NMEA 0183 Interface Standard is used worldwide across many industry segments. The standard defines electrical signal requireme... National Marine Electronics Association (NMEA) Garmin Proprietary NMEA 0183 Sentence TECHNICAL ... Apr 21, 2006 —
This comprehensive guide explores the NMEA 0183 standard , detailing its sentence structures and data types to help you understand and parse marine navigation messages effectively. What is NMEA 0183? NMEA 0183 is a combined electrical and data specification developed by the National Marine Electronics Association (NMEA) for communication between marine electronic devices like GPS receivers, autopilots, and depth sounders. It uses a simple ASCII serial protocol to transmit data from a single "talker" to one or more "listeners". Standard NMEA 0183 Sentence Structure Every standard NMEA 0183 sentence follows a strict format to ensure cross-manufacturer compatibility:
NMEA 0183 Sentences: A Comprehensive Guide for Marine Data Interfacing Introduction In the world of marine electronics, seamless communication between devices is paramount. Whether it is a GPS receiver sending coordinates to an autopilot or a depth sounder sending data to a chart plotter, these devices must speak a common language. The standard dialect for this communication for decades has been the NMEA 0183 standard. While the newer NMEA 2000 standard (based on CAN-bus technology) is gaining ground, NMEA 0183 remains the "lingua franca" for millions of legacy devices and many modern budget-friendly instruments. This article breaks down the structure of NMEA 0183 sentences, the most common message types, and how to parse them effectively. What is NMEA 0183? NMEA 0183 is a combined electrical and data specification for communication between marine electronics such as echo sounders, sonars, anemometers, GPS receivers, gyrocompasses, and autopilots. It is defined and controlled by the National Marine Electronics Association (NMEA). The standard uses a simple serial interface. The data is transmitted in readable ASCII text "sentences" from a "talker" (output device) to a "listener" (input device). The Anatomy of an NMEA Sentence NMEA data is streamed as lines of text. Each distinct line is called a "sentence." Every sentence begins with a dollar sign ( $ ) and ends with a carriage return and line feed ( <CR><LF> ). Breakdown of a Sample Sentence Consider this standard GPS position sentence: $GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 Here is how we parse this string: nmea 0183 sentences pdf
$ : The start delimiter. GP : The Talker ID . This identifies the type of device sending the data. GP typically represents a GPS receiver. Other common IDs include SD (Sounder/Depth), WI (Weather Instrument), and EC (Electronic Chart Display). GGA : The Sentence Formatter . This tells the listener what kind of data follows. GGA is the standard "Global Positioning System Fix Data." , , , ,...` : Commas separate the data fields. * : The checksum delimiter. It signifies that the next two characters are a hexadecimal checksum. 47 : The Checksum . This is calculated by XORing all bytes between the $ and the * . It ensures the data arrived without corruption.
Common NMEA 0183 Sentence Types While there are dozens of standard sentences, a handful covers the vast majority of marine interfacing needs. 1. GPS and Position Data ( GP )
GPGGA (Global Positioning System Fix Data): Provides essential fix data: time, latitude, longitude, fix quality (valid/invalid), number of satellites, horizontal dilution of precision (HDOP), altitude, and height of geoid. GPRMC (Recommended Minimum Specific GPS/Transit Data): Perhaps the most common sentence. It contains time, status (valid/void), latitude, longitude, speed over ground (knots), track made good (degrees), and date. This is often the primary sentence used by software to update vessel position. GPVTG (Track Made Good and Ground Speed): Provides the actual track and speed relative to the ground. NMEA 0183 is a combined electrical and data
2. Navigation and Route Data ( EC / GP )
GPAPB (Autopilot Sentence "B"): Contains heading to steer, cross-track error, and waypoint data. This is critical for autopilots to follow a route. GPBOD (Bearing - Origin to Destination): The bearing from the current location to a destination waypoint.
3. Depth and Speed Through Water ( SD / VW ) Sentence Format : All standard sentences start with
SDDBT (Depth Below Transducer): Provides depth readings in feet, meters, and fathoms. VWVHW (Water Speed and Heading): Provides speed through the water and heading relative to the vessel's magnetic compass.
4. Wind Data ( WI )