NMEA 0183 Standard

1. What is the NMEA 0183 Standard? The National Marine Electronics Association (NMEA) is a non-profit association of manufacturers, distributors, dealers, educational institutions, and others interested in peripheral marine electronics occupations. The NMEA 0183 standard defines an electrical interface and data protocol for communications between marine instrumentation. NMEA 0183 is a voluntary industry standard, first released in March of 1983. It has been updated from time to time; the latest release, currently (August 2001) Version 3.0, July 2001, is available from the NMEA office (Warning: the price for non-members is 250 US$). P O Box 3435 New Bern NC 28564-3435 USA www.nmea.org NMEA has also established a working group to develop a new standard for data communications among shipboard electronic devices. The new standard, NMEA 2000, is a bi-directional, multi-transmitter, multi-receiver serial data network. It is multi-master and self-configuring, and there is no central controller. The NMEA began a beta testing period in January 2000 with eleven manufacturers. A release version of NMEA 2000 is expected in 2001.

2. Electrical Interface NMEA 0183 devices are designated as either talkers or listeners (with some devices being both), employing an asynchronous serial interface with the following parameters: Baud rate: 4800 Number of data bits: 8 (bit 7 is 0) Stop bits: 1 (or more) Parity: none Handshake: none NMEA 0183 allows a single talker and several listeners on one circuit. The recommended interconnect wiring is a shielded twisted pair, with the shield grounded only at the talker. The standard dos not specify the use of a particular connector. Note: The new 0183-HS standard (HS = high speed) introduced in version 3.0 uses a 3-wire interface and a baud rate of 38400. This type of interface is not discussed here. Its is recommended that the talker output comply with EIA RS-422, a differential system with two signal lines, “A” and “B”. Differential drive signals have no reference to ground and are more immune to noise. However, a single-ended line at TTL level is accepted as well. The voltages on the A line correspond to those on the TTL single wire, while the B voltages are inverted (when output A is at +5 V, output B is at 0 V, and vice versa. This is the unipolar RS-422 operation. In bipolar mode ±5 V are used). In either case, the recommended receive circuit uses an opto-isolator with suitable protection circuitry. The input should be isolated from the receiver’s ground. In practice, the single wire, or the RS-422 “A” wire may be directly connected to a computer’s RS-232 input. In fact even many of the latest products, like hand-held GPS receivers, do not have a RS-422 differential output, but just a single line with TTL or 5 V CMOS compatible signal level.

3. General Sentence Format All data is transmitted in the form of sentences. Only printable ASCII characters are allowed, plus CR (carriage return) and LF (line feed). Each sentence starts with a ”$” sign and ends with <CR><LF>. There are three basic kinds of sentences: talker sentences, proprietary sentences and query sentences. Talker Sentences. The general format for a talker sentence is: $ttsss,d1,d2,…<CR><LF> The first two letters following the „$” are the talker identifier. The next three characters (sss) are the sentence identifier, followed by a number of data fields separated by commas, followed by an optional checksum, and terminated by carriage return/line feed. The data fields are uniquely defined for each sentence type. An example talker sentence is: $HCHDM,238,M<CR><LF> where “HC” specifies the talker as being a magnetic compass, the “HDM” specifies the magnetic heading message follows. The “238” is the heading value, and “M” designates the heading value as magnetic. A sentence may contain up to 80 characters plus ”$” and CR/LF. If data for a field is not available, the field is omitted, but the delimiting commas are still sent, with no space between them. The checksum field consists of a ”*” and two hex digits representing the exclusive OR of all characters between, but not including, the ”$” and ”*”. Proprietary Sentences. The standard allows individual manufacturers to define proprietary sentence formats. These sentences start with “$P”, then a 3 letter manufacturer ID, followed by whatever data the manufacturer wishes, following the general format of the standard sentences. Some proprietary sentences, mainly from Garmin, Inc., are listed in chapter 6.

Query sentences. A query sentence is a means for a listener to request a particular sentence from a talker. The general format is: $ttllQ,sss,[CR][LF] The first two characters of the address field are the talker identifier of the requester and the next two characters are the talker identifier of the device being queried (listener). The fifth character is always a “Q” defining the message as a query. The next field (sss) contains the three letter mnemonic of the sentence being requested. An example query sentence is: $CCGPQ,GGA<CR><LF> where the “CC” device (computer) is requesting from the “GP” device (a GPS unit) the “GGA” sentence. The GPS will then transmit this sentence once per second until a different query is requested. 4. Talker Identifiers AG Autopilot - General AP Autopilot - Magnetic CD Communications – Digital Selective Calling (DSC) CR Communications – Receiver / Beacon Receiver CS Communications – Satellite CT Communications – Radio-Telephone (MF/HF) CV Communications – Radio-Telephone (VHF) CX Communications – Scanning Receiver DF Direction Finder EC Electronic Chart Display & Information System (ECDIS) EP Emergency Position Indicating Beacon (EPIRB) ER Engine Room Monitoring Systems GP Global Positioning System (GPS) HC Heading – Magnetic Compass HE Heading – North Seeking Gyro HN Heading – Non North Seeking Gyro II Integrated Instrumentation IN Integrated Navigation LC Loran C P Proprietary Code RA RADAR and/or ARPA SD Sounder, Depth SN Electronic Positioning System, other/general SS Sounder, Scanning TI Turn Rate Indicator VD Velocity Sensor, Doppler, other/general DM Velocity Sensor, Speed Log, Water, Magnetic VW Velocity Sensor, Speed Log, Water, Mechanical WI Weather Instruments YX Transducer ZA Timekeeper – Atomic Clock ZC Timekeeper – Chronometer ZQ Timekeeper – Quartz ZV Timekeeper – Radio Update, WWV or WWVH

5. Sentence Identifiers and Formats AAM Waypoint Arrival Alarm 1 2 3 4 5 6 | | | | | | $—AAM,A,A,x.x,N,c—c*hh

1. Status, BOOLEAN, A = Arrival circle entered
2. Status, BOOLEAN, A = perpendicular passed at waypoint
3. Arrival circle radius
4. Units of radius, nautical miles
5. Waypoint ID
6. Checksum ALM GPS Almanac Data 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | | | | | | | | | | | | | | | | $—ALM,x.x,x.x,xx,x.x,hh,hhhh,hh,hhhh,hhhh,hhhhhh,hhhhhh,hhhhhh,hhhhhh,hhh,hhh,*hh
7. Total number of messages
8. Message Number
9. Satellite PRN number (01 to 32)
10. GPS Week Number: Date and time in GPS is computed as number of weeks from 6 January 1980 plus number of seconds into the week.
11. SV health, bits 17-24 of each almanac page
12. Eccentricity
13. Almanac Reference Time
14. Inclination Angle
15. Rate of Right Ascension
16. Root of semi-major axis
17. Argument of perigee
18. Longitude of ascension node
19. Mean anomaly
20. F0 Clock Parameter
21. F1 Clock Parameter
22. Checksum APA Autopilot Sentence “A” 1 2 3 4 5 6 7 8 9 10 11 | | | | | | | | | | | $—APA,A,A,x.xx,L,N,A,A,xxx,M,c---c*hh
23. Status V = LORAN-C Blink or SNR warning A = general warning flag or other navigation systems when a reliable fix is not available
24. Status V = Loran-C Cycle Lock warning flag A = OK or not used
25. Cross Track Error Magnitude
26. Direction to steer, L or R
27. Cross Track Units (Nautic miles or kilometres)
28. Status A = Arrival Circle Entered
29. Status A = Perpendicular passed at waypoint
30. Bearing origin to destination
31. M = Magnetic, T = True
32. Destination Waypoint ID
33. checksum

APB Autopilot Sentence “B” 13 15 1 2 3 4 5 6 7 8 9 10 11 12| 14| | | | | | | | | | | | | | | | $—APB,A,A,x.x,a,N,A,A,x.x,a,c—c,x.x,a,x.x,a*hh

1. Status V = LORAN-C Blink or SNR warning A = general warning flag or other navigation systems when a reliable fix is not available
2. Status V = Loran-C Cycle Lock warning flag A = OK or not used
3. Cross Track Error Magnitude
4. Direction to steer, L or R
5. Cross Track Units, N = Nautical Miles
6. Status A = Arrival Circle Entered
7. Status A = Perpendicular passed at waypoint
8. Bearing origin to destination
9. M = Magnetic, T = True
10. Destination Waypoint ID
11. Bearing, present position to Destination
12. M = Magnetic, T = True
13. Heading to steer to destination waypoint
14. M = Magnetic, T = True
15. Checksum ASD Autopilot System Data Format unknown BEC Bearing & Distance to Waypoint – Dead Reckoning 12 1 2 3 4 5 6 7 8 9 10 11| 13 | | | | | | | | | | | | | $—BEC,hhmmss.ss,llll.ll,a,yyyyy.yy,a,x.x,T,x.x,M,x.x,N,c—c*hh
16. Time (UTC)
17. Waypoint Latitude
18. N = North, S = South
19. Waypoint Longitude
20. E = East, W = West
21. Bearing, True
22. T = True
23. Bearing, Magnetic
24. M = Magnetic
25. Nautical Miles
26. N = Nautical Miles
27. Waypoint ID
28. Checksum

BOD Bearing – Waypoint to Waypoint 1 2 3 4 5 6 7 | | | | | | | $—BOD,x.x,T,x.x,M,c—c,c—c*hh

1. Bearing Degrees, TRUE
2. T = True
3. Bearing Degrees, Magnetic
4. M = Magnetic
5. TO Waypoint
6. FROM Waypoint
7. Checksum BWC Bearing and Distance to Waypoint – Latitude, N/S, Longitude, E/W, UTC, Status 11 1 2 3 4 5 6 7 8 9 10 | 12 13 | | | | | | | | | | | | | $—BWC,hhmmss.ss,llll.ll,a,yyyyy.yy,a,x.x,T,x.x,M,x.x,N,c—c*hh
8. Time (UTC)
9. Waypoint Latitude
10. N = North, S = South
11. Waypoint Longitude
12. E = East, W = West
13. Bearing, True
14. T = True
15. Bearing, Magnetic
16. M = Magnetic
17. Nautical Miles
18. N = Nautical Miles
19. Waypoint ID
20. Checksum BWR Bearing and Distance to Waypoint – Rhumb Line Latitude, N/S, Longitude, E/W, UTC, Status 11 1 2 3 4 5 6 7 8 9 10 | 12 13 | | | | | | | | | | | | | $—BWR,hhmmss.ss,llll.ll,a,yyyyy.yy,a,x.x,T,x.x,M,x.x,N,c—c*hh
21. Time (UTC)
22. Waypoint Latitude
23. N = North, S = South
24. Waypoint Longitude
25. E = East, W = West
26. Bearing, True
27. T = True
28. Bearing, Magnetic
29. M = Magnetic
30. Nautical Miles
31. N = Nautical Miles
32. Waypoint ID
33. Checksum

BWW Bearing – Waypoint to Waypoint 1 2 3 4 5 6 7 | | | | | | | $—BWW,x.x,T,x.x,M,c—c,c—c*hh

1. Bearing Degrees, TRUE
2. T = True
3. Bearing Degrees, Magnetic
4. M = Magnetic
5. TO Waypoint
6. FROM Waypoint
7. Checksum DBK Depth Below Keel 1 2 3 4 5 6 7 | | | | | | | $—DBK,x.x,f,x.x,M,x.x,F*hh
8. Depth, feet
9. f = feet
10. Depth, meters
11. M = meters
12. Depth, Fathoms
13. F = Fathoms
14. Checksum DBS Depth Below Surface 1 2 3 4 5 6 7 | | | | | | | $—DBS,x.x,f,x.x,M,x.x,F*hh
15. Depth, feet
16. f = feet
17. Depth, meters
18. M = meters
19. Depth, Fathoms
20. F = Fathoms
21. Checksum DBT Depth Below Transducer 1 2 3 4 5 6 7 | | | | | | | $—DBT,x.x,f,x.x,M,x.x,F*hh
22. Depth, feet
23. f = feet
24. Depth, meters
25. M = meters
26. Depth, Fathoms
27. F = Fathoms
28. Checksum DCN Decca Position obsolete

DPT Heading – Deviation & Variation 1 2 3 | | | $—DPT,x.x,x.x*hh

1. Depth, meters
2. Offset from transducer; positive means distance from transducer to water line, negative means distance from transducer to keel
3. Checksum DSC Digital Selective Calling Information Format unknown DSE Extended DSC Format unknown DSI DSC Transponder Initiate Format unknown DSR DSC Transponder Response Format unknown DTM Datum Reference Format unknown FSI Frequency Set Information 1 2 3 4 5 | | | | | $—FSI,xxxxxx,xxxxxx,c,x*hh
4. Transmitting Frequency
5. Receiving Frequency
6. Communications Mode (NMEA Syntax 2)
7. Power Level
8. Checksum GBS GPS Satellite Fault Detection Format unknown

GGA Global Positioning System Fix Data. Time, Position and fix related data for a GPS receiver 11 1 2 3 4 5 6 7 8 9 10 | 12 13 14 15 | | | | | | | | | | | | | | | $—GGA,hhmmss.ss,llll.ll,a,yyyyy.yy,a,x,xx,x.x,x.x,M,x.x,M,x.x,xxxx*hh

1. Time (UTC)
2. Latitude
3. N or S (North or South)
4. Longitude
5. E or W (East or West)
6. GPS Quality Indicator, 0 - fix not available, 1 - GPS fix, 2 - Differential GPS fix
7. Number of satellites in view, 00 - 12
8. Horizontal Dilution of precision
9. Antenna Altitude above/below mean-sea-level (geoid)
10. Units of antenna altitude, meters
11. Geoidal separation, the difference between the WGS-84 earth ellipsoid and mean-sea-level (geoid), ”-” means mean-sea-level below ellipsoid
12. Units of geoidal separation, meters
13. Age of differential GPS data, time in seconds since last SC104 type 1 or 9 update, null field when DGPS is not used
14. Differential reference station ID, 0000-1023
15. Checksum GLC Geographic Position, Loran-C 12 14 1 2 3 4 5 6 7 8 9 10 11| 13| | | | | | | | | | | | | | | $—GLC,xxxx,x.x,a,x.x,a,x.x,a.x,x,a,x.x,a,x.x,a*hh
16. GRI Microseconds/10
17. Master TOA Microseconds
18. Master TOA Signal Status
19. Time Difference 1 Microseconds
20. Time Difference 1 Signal Status
21. Time Difference 2 Microseconds
22. Time Difference 2 Signal Status
23. Time Difference 3 Microseconds
24. Time Difference 3 Signal Status
25. Time Difference 4 Microseconds
26. Time Difference 4 Signal Status
27. Time Difference 5 Microseconds
28. Time Difference 5 Signal Status
29. Checksum GLL Geographic Position – Latitude/Longitude 1 2 3 4 5 6 7 | | | | | | | $—GLL,llll.ll,a,yyyyy.yy,a,hhmmss.ss,A*hh
30. Latitude
31. N or S (North or South)
32. Longitude
33. E or W (East or West)
34. Time (UTC)
35. Status A - Data Valid, V - Data Invalid
36. Checksum

GRS GPS Range Residuals Format unknown GST GPS Pseudorange Noise Statistics Format unknown GSA GPS DOP and active satellites 1 2 3 14 15 16 17 18 | | | | | | | | $—GSA,a,a,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x.x,x.x,x.x*hh

1. Selection mode
2. Mode
3. ID of 1st satellite used for fix
4. ID of 2nd satellite used for fix …
5. ID of 12th satellite used for fix
6. PDOP in meters
7. HDOP in meters
8. VDOP in meters
9. Checksum GSV Satellites in view 1 2 3 4 5 6 7 n | | | | | | | | $—GSV,x,x,x,x,x,x,x,…*hh
10. total number of messages
11. message number
12. satellites in view
13. satellite number
14. elevation in degrees
15. azimuth in degrees to true
16. SNR in dB more satellite infos like 4)-7) n) Checksum GTD Geographic Location in Time Differences 1 2 3 4 5 6 | | | | | | $—GTD,x.x,x.x,x.x,x.x,x.x*hh
17. time difference
18. time difference
19. time difference
20. time difference
21. time difference n) Checksum GXA TRANSIT Position – Latitude/Longitude, Location and Time of TRANSIT Fix at Waypoint obsolete

HDG Heading – Deviation & Variation 1 2 3 4 5 6 | | | | | | $—HDG,x.x,x.x,a,x.x,a*hh

1. Magnetic Sensor heading in degrees
2. Magnetic Deviation, degrees
3. Magnetic Deviation direction, E = Easterly, W = Westerly
4. Magnetic Variation degrees
5. Magnetic Variation direction, E = Easterly, W = Westerly
6. Checksum HDM Heading – Magnetic 1 2 3 | | | $—HDM,x.x,M*hh
7. Heading Degrees, magnetic
8. M = magnetic
9. Checksum HDT Heading – True 1 2 3 | | | $—HDT,x.x,T*hh
10. Heading Degrees, true
11. T = True
12. Checksum HSC Heading Steering Command 1 2 3 4 5 | | | | | $—HSC,x.x,T,x.x,M,*hh
13. Heading Degrees, True
14. T = True
15. Heading Degrees, Magnetic
16. M = Magnetic
17. Checksum

LCD Loran-C Signal Data 1 2 3 4 5 6 7 8 9 10 11 12 13 14 | | | | | | | | | | | | | | $—LCD,xxxx,xxx,xxx,xxx,xxx,xxx,xxx,xxx,xxx,xxx,xxx,xxx,xxx*hh

1. GRI Microseconds/10
2. Master Relative SNR
3. Master Relative ECD
4. Time Difference 1 Microseconds
5. Time Difference 1 Signal Status
6. Time Difference 2 Microseconds
7. Time Difference 2 Signal Status
8. Time Difference 3 Microseconds
9. Time Difference 3 Signal Status
10. Time Difference 4 Microseconds
11. Time Difference 4 Signal Status
12. Time Difference 5 Microseconds
13. Time Difference 5 Signal Status
14. Checksum MSK MSK Receiver Interface (for DGPS Beacon Receivers) 1 2 3 4 5 6 | | | | | | $GPMSK,xxx.x,xx,xxx,xx,N*hh
15. Frequency in kHz (283.5 to 325.0)
16. Frequency Selection M1 = Manual A1 = Automatic (field 1 empty)
17. MSK bit rate (100 or 200)
18. Bit Rate Selection M2 = Manual A2 = Automatic (field 3 empty)
19. Period of output of performance status message, 0 to 100 seconds ($CRMSS)
20. Checksum MSS MSK Receiver Signal Status Format unknown MWD Wind Direction & Speed Format unknown MTW Water Temperature 1 2 3 | | | $—MTW,x.x,C*hh
21. Degrees
22. Unit of Measurement, Celcius
23. Checksum

MWV Wind Speed and Angle 1 2 3 4 5 | | | | | $—MWV,x.x,a,x.x,a*hh

1. Wind Angle, 0 to 360 degrees
2. Reference, R = Relative, T = True
3. Wind Speed
4. Wind Speed Units, K/M/N
5. Status, A = Data Valid
6. Checksum OLN Omega Lane Numbers obsolete OSD Own Ship Data 1 2 3 4 5 6 7 8 9 10 | | | | | | | | | | $—OSD,x.x,A,x.x,a,x.x,a,x.x,x.x,a*hh
7. Heading, degrees true
8. Status, A = Data Valid
9. Vessel Course, degrees True
10. Course Reference
11. Vessel Speed
12. Speed Reference
13. Vessel Set, degrees True
14. Vessel drift (speed)
15. Speed Units
16. Checksum ROO Waypoints in Active Route 1 n | | $—ROO,c---c,c---c,…*hh
17. waypoint ID … n) checksum RMA Recommended Minimum Navigation Information 12 1 2 3 4 5 6 7 8 9 10 11| | | | | | | | | | | | | $—RMA,A,llll.ll,a,yyyyy.yy,a,x.x,x.x,x.x,x.x,x.x,a*hh
18. Blink Warning
19. Latitude
20. N or S
21. Longitude
22. E or W
23. Time Difference A, µS
24. Time Difference B, µS
25. Speed Over Ground, Knots
26. Track Made Good, degrees true
27. Magnetic Variation, degrees
28. E or W
29. Checksum

RMB Recommended Minimum Navigation Information 14 1 2 3 4 5 6 7 8 9 10 11 12 13| | | | | | | | | | | | | | | $—RMB,A,x.x,a,c—c,c—c,llll.ll,a,yyyyy.yy,a,x.x,x.x,x.x,A*hh

1. Status, V = Navigation receiver warning
2. Cross Track error - nautical miles
3. Direction to Steer, Left or Right
4. TO Waypoint ID
5. FROM Waypoint ID
6. Destination Waypoint Latitude
7. N or S
8. Destination Waypoint Longitude
9. E or W
10. Range to destination in nautical miles
11. Bearing to destination in degrees True
12. Destination closing velocity in knots
13. Arrival Status, A = Arrival Circle Entered
14. Checksum RMC Recommended Minimum Navigation Information 12 1 2 3 4 5 6 7 8 9 10 11| | | | | | | | | | | | | $—RMC,hhmmss.ss,A,llll.ll,a,yyyyy.yy,a,x.x,x.x,xxxx,x.x,a*hh
15. Time (UTC)
16. Status, V = Navigation receiver warning
17. Latitude
18. N or S
19. Longitude
20. E or W
21. Speed over ground, knots
22. Track made good, degrees true
23. Date, ddmmyy
24. Magnetic Variation, degrees
25. E or W
26. Checksum ROT Rate Of Turn 1 2 3 | | | $—ROT,x.x,A*hh
27. Rate Of Turn, degrees per minute, ”-” means bow turns to port
28. Status, A means data is valid
29. Checksum RPM Revolutions 1 2 3 4 5 6 | | | | | | $—RPM,a,x,x.x,x.x,A*hh
30. Source; S = Shaft, E = Engine
31. Engine or shaft number
32. Speed, Revolutions per minute
33. Propeller pitch, % of maximum, ”-” means astern
34. Status, A means data is valid
35. Checksum

RSA Rudder Sensor Angle 1 2 3 4 5 | | | | | $—RSA,x.x,A,x.x,A*hh

1. Starboard (or single) rudder sensor, ”-” means Turn To Port
2. Status, A means data is valid
3. Port rudder sensor
4. Status, A means data is valid
5. Checksum RSD RADAR System Data 14 1 2 3 4 5 6 7 8 9 10 11 12 13| | | | | | | | | | | | | | | $—RSD,x.x,x.x,x.x,x.x,x.x,x.x,x.x,x.x,x.x,x.x,x.x,a,a*hh
6. Cursor Range From Own Ship
7. Cursor Bearing Degrees Clockwise From Zero
8. Range Scale
9. Range Units
10. Checksum RTE Routes 1 2 3 4 5 x n | | | | | | | $—RTE,x.x,x.x,a,c—c,c—c, … c—c*hh
11. Total number of messages being transmitted
12. Message Number
13. Message mode c = complete route, all waypoints w = working route, the waypoint you just left, the waypoint you’re heading to, then all the rest
14. Waypoint ID x) More Waypoints n) Checksum SFI Scanning Frequency Information 1 2 3 4 n | | | | | $—SFI,x.x,x.x,xxxxxx,c … xxxxxx,c*hh
15. Total Number Of Messages
16. Message Number
17. Frequency 1
18. Mode 1 n) Checksum STN Multiple Data ID 1 2 | | $—STN,x.x,*hh
19. Talker ID Number
20. Checksum

TLL Target Latitude and Longitude Format unknown TRF TRANSIT Fix Data obsolete TTM Tracked Target Message 11 13 1 2 3 4 5 6 7 8 9 10| 12| 14 | | | | | | | | | | | | | | $—TTM,xx,x.x,x.x,a,x.x,x.x,a,x.x,x.x,a,c—c,a,a*hh

1. Target Number
2. Target Distance
3. Bearing from own ship
4. Bearing Units
5. Target speed
6. Target Course
7. Course Units
8. Distance of closest-point-of-approach
9. Time until closest-point-of-approach ”-” means increasing
10. ”-” means increasing
11. Target name
12. Target Status
13. Reference Target
14. Checksum VBW Dual Ground/Water Speed 1 2 3 4 5 6 7 | | | | | | | $—VBW,x.x,x.x,A,x.x,x.x,A*hh
15. Longitudinal water speed, ”-” means astern
16. Transverse water speed, ”-” means port
17. Status, A = data valid
18. Longitudinal ground speed, ”-” means astern
19. Transverse ground speed, ”-” means port
20. Status, A = data valid
21. Checksum VDR Set and Drift 1 2 3 4 5 6 7 | | | | | | | $—VDR,x.x,T,x.x,M,x.x,N*hh
22. Degress True
23. T = True
24. Degrees Magnetic
25. M = Magnetic
26. Knots (speed of current)
27. N = Knots
28. Checksum

VHW Water Speed and Heading 1 2 3 4 5 6 7 8 9 | | | | | | | | | $—VHW,x.x,T,x.x,M,x.x,N,x.x,K*hh

1. Degress True
2. T = True
3. Degrees Magnetic
4. M = Magnetic
5. Knots (speed of vessel relative to the water)
6. N = Knots
7. Kilometers (speed of vessel relative to the water)
8. K = Kilometres
9. Checksum VLW Distance Traveled through Water 1 2 3 4 5 | | | | | $—VLW,x.x,N,x.x,N*hh
10. Total cumulative distance
11. N = Nautical Miles
12. Distance since Reset
13. N = Nautical Miles
14. Checksum VPW Speed – Measured Parallel to Wind 1 2 3 4 5 | | | | | $—VPW,x.x,N,x.x,M*hh
15. Speed, ”-” means downwind
16. N = Knots
17. Speed, ”-” means downwind
18. M = Meters per second
19. Checksum VTG Track Made Good and Ground Speed 1 2 3 4 5 6 7 8 9 | | | | | | | | | $—VTG,x.x,T,x.x,M,x.x,N,x.x,K*hh
20. Track Degrees
21. T = True
22. Track Degrees
23. M = Magnetic
24. Speed Knots
25. N = Knots
26. Speed Kilometers Per Hour
27. K = Kilometres Per Hour
28. Checksum

VWR Relative Wind Speed and Angle 1 2 3 4 5 6 7 8 9 | | | | | | | | | $—VWR,x.x,a,x.x,N,x.x,M,x.x,K*hh

1. Wind direction magnitude in degrees
2. Wind direction Left/Right of bow
3. Speed
4. N = Knots
5. Speed
6. M = Meters Per Second
7. Speed
8. K = Kilometers Per Hour
9. Checksum WCV Waypoint Closure Velocity 1 2 3 4 | | | | $—WCV,x.x,N,c—c*hh
10. Velocity
11. N = knots
12. Waypoint ID
13. Checksum WDC Distance to Waypoint – Great Circle Format unknown WDR Distance to Waypoint – Rhumb Line Format unknown WNC Distance – Waypoint to Waypoint 1 2 3 4 5 6 7 | | | | | | | $—WNC,x.x,N,x.x,K,c—c,c—c*hh
14. Distance, Nautical Miles
15. N = Nautical Miles
16. Distance, Kilometers
17. K = Kilometers
18. TO Waypoint
19. FROM Waypoint
20. Checksum WPL Waypoint Location 1 2 3 4 5 6 | | | | | | $—WPL,llll.ll,a,yyyyy.yy,a,c—c*hh
21. Latitude
22. N or S (North or South)
23. Longitude
24. E or W (East or West)
25. Waypoint Name
26. Checksum

XDR Cross Track Error – Dead Reckoning 1 2 3 4 n | | | | | $—XDR,a,x.x,a,c—c, … *hh

1. Transducer type
2. Measurement data
3. Units of measurement
4. Name of transducer x) More of the same n) Checksum XTE Cross-Track Error – Measured 1 2 3 4 5 6 | | | | | | $—XTE,A,A,x.x,a,N,*hh
5. Status V = LORAN-C blink or SNR warning A = general warning flag or other navigation systems when a reliable fix is not available
6. Status V = Loran-C cycle lock warning flag A = OK or not used
7. Cross track error magnitude
8. Direction to steer, L or R
9. Cross track units. N = Nautical Miles
10. Checksum XTR Cross Track Error – Dead Reckoning 1 2 3 4 | | | | $—XTR,x.x,a,N*hh
11. Magnitude of cross track error
12. Direction to steer, L or R
13. Units, N = Nautical Miles
14. Checksum ZDA Time & Date – UTC, Day, Month, Year and Local Time Zone 1 2 3 4 5 6 7 | | | | | | | $—ZDA,hhmmss.ss,xx,xx,xxxx,xx,xx*hh
15. Local zone minutes description, same sign as local hours
16. Local zone description, 00 to +/- 13 hours
17. Year
18. Month, 01 to 12
19. Day, 01 to 31
20. Time (UTC)
21. Checksum ZDL Time and Distance to Variable Point Format unknown

ZFO UTC & Time from Origin Waypoint 1 2 3 4 | | | | $—ZFO,hhmmss.ss,hhmmss.ss,c—c*hh

1. Time (UTC)
2. Elapsed Time
3. Origin Waypoint ID
4. Checksum ZTG UTC & Time to Destination Waypoint 1 2 3 4 | | | | $—ZTG,hhmmss.ss,hhmmss.ss,c—c*hh
5. Time (UTC)
6. Time Remaining
7. Destination Waypoint ID
8. Checksum

6. Some Proprietary Sentences $PGRMC Sensor Configuration Information Garmin proprietary sentence 13 14 1 2 3 4 5 6 7 8 9 10| 12| | | | | | | | | | | | | | $PGRMC,A,x.x,hh,x.x,x.x,x.x,x.x,x.x,c,c,2,c*hh

1. Fix mode, A=automatic (only option)
2. Altitude above/below mean sea level, -1500.0 to 18000.0 meters
3. Earth datum index. If the user datum index (96) is specified, fields 5-8 must contain valid values. Otherwise, fields 4-8 must be null.
4. User earth datum semi-major axis, 6360000.0 to 6380000.0 meters (.001 meters resolution)
5. User earth datum inverse flattening factor, 285.0 to 310.0 (10-9 resolution)
6. User earth datum delta x earth centered coordinate, -5000.0 to 5000.0 meters (1 meter resolution)
7. User earth datum delta y earth centered coordinate, -5000.0 to 5000.0 meters (1 meter resolution)
8. User earth datum delta z earth centered coordinate, -5000.0 to 5000.0 meters (1 meter resolution)
9. Differential mode, A = automatic (output DGPS data when available, non-DGPs otherwise), D = differential exclusively (output only differential fixes)
10. NMEA Baud rate, 1 = 1200, 2 = 2400, 3 = 4800, 4 = 9600
11. Filter mode, 2 = no filtering (only option)
12. PPS mode, 1 = No PPS, 2 = 1 Hz
13. Checksum $PGRME Estimated Position Error Garmin proprietary sentence 1 2 3 4 5 6 7 | | | | | | | $PGRME,x.x,M,x.x,M,x.x,M*hh
14. Estimated horizontal position error (HPE)
15. Unit, metres
16. Estimated vertical error (VPE)
17. Unit, metres
18. Overall spherical equivalent position error
19. Unit, metres
20. Checksum

$PGRMF Position Fix Sentence Garmin proprietary sentence 10 12 15 1 2 3 4 5 6 7 8 9 | 11| 13 14| 16 | | | | | | | | | | | | | | | | $PGRMF,x.x,x.x,ddmmyy,hhmmss,x.x,ddmm.mmmm,c,dddmm.mmmm,c,c,c,x.x,x.x,c,c*hh

1. GPS week number (0 - 1023)
2. GPS seconds (0 - 604799)
3. UTC date of position fix
4. UTC time of position fix
5. GPS leap second count
6. Latitude
7. N or S
8. Longitude
9. E or W
10. Mode M = manual A = automatic
11. Fix type 0 = no fix 1 = 2D fix 2 = 3D fix
12. Speed over ground, 0 to 999 kilometers/hour
13. Course over ground, 0 to 359 degrees, true
14. Position dilution of precision, 0 to 9 (rounded to nearest integer value)
15. Time dilution of precision, 0 to 9 (rounded to nearest integer value)
16. Checksum $PGRMI Sensor Initialisation Information Garmin proprietary sentence 1 2 3 4 5 6 7 | | | | | | | $PGRMI,ddmm.mmm,N,ddmm.mmm,E,ddmmyy,hhmmss*hh
17. Latitude
18. N or S
19. Longitude
20. E or W
21. Current UTC date
22. Current UTC time
23. Checksum $PGRMM Map Datum Garmin proprietary sentence 1 2 | | $PGRMM,c---c*hh
24. Currently active horizontal datum (WGS-84, NAD27 Canada, ED50, a.s.o)
25. Checksum

$PGRMO Output Sentence Enable/Disable Garmin proprietary sentence 1 2 3 | | | $PGRMO,ccccc,c*hh

1. Target sentence description (e.g., PGRMT, GPGSV, etc.)
2. Target sentence mode 0 = disable specified sentence 1 = enable specified sentence 2 = disable all 3 = enable all output sentences (except GPALM)
3. Checksum $PGRMT Sensor Status Information Garmin proprietary sentence 1 2 3 4 5 6 7 8 9 10 | | | | | | | | | | $PGRMT,c…c,c,c,c,c,c,c,x.x,c*hh
4. Product, model and software version e.g. “GPS25VEE] 1.10”
5. Rom checksum test P = pass F = fail
6. Receiver failure discrete P = pass F = fail
7. Stored data lost R = retained L = lost
8. Real time clock lost R = retained L = lost
9. 0scillator drift discrete P = pass F = excessive drift detected
10. Data collection discrete C = collecting null if not collecting
11. Board temperature in degrees C
12. Board configuration data R = retained L = lost
13. Checksum $PGRMV 3D Velocity Garmin proprietary sentence 1 2 3 4 | | | | $PGRMV,x.x,x.x,x.x*hh
14. True east velocity, -999.9 to 9999.9 meters/second
15. True north velocity, -999.9 to 9999.9 meters/second
16. Up velocity, -999.9 to 9999.9 meters/second
17. Checksum

$PGRMZ Altitude Information Garmin proprietary sentence 1 2 3 4 | | | | $PGRMZ,x.x,f,h*hh

1. Altitude
2. Unit, feets
3. Position fix dimensions 2 user altitude 3 GPS altitude
4. Checksum $PSLIB Differental GPS Beacon Receiver Control Starlink, Inc. proprietary sentence, used by Garmin and others 1 2 3 4 | | | | $PSLIB,x.x,x.x,c*hh
5. Frequency
6. Bit rate
7. Request type J = status request K = configuration request blank = tuning message
8. Checksum

7. Manufacturer Codes Note: This list is out-of-date, but perhaps still useful. AAR Asian American Resources ACE Auto-Comm Engineering Corporation ACR ACR Electronics, Inc. ACS Arco Solar, Inc. ACT Advanced Control Technology AGI Airguide Instrument Company AHA Autohelm of America AIP Aiphone Corporation ALD Alden Electronics, Inc. AMR AMR Systems AMT Airmar Technology ANS Antenna Specialists ANX Analytyx Electronic Systems ANZ Anschutz of America APC Apelco APN American Pioneer, Inc. APX Amperex, Inc. AQC Aqua-Chem, Inc. AQD Aquadynamics, Inc. AQM Aqua Meter Instrument Company ASP American Solar Power ATE Aetna Engineering ATM Atlantic Marketing Company, Inc. ATR Airtron ATV Activation, Inc. AVN Advanced Navigation, Inc. AWA Awa New Zealand, Limited BBL BBL Industries, Inc. BBR BBR and Associates BDV Brisson Development, Inc. BEC Boat Electric Company BGS Barringer Geoservice BGT Brookes and Gatehouse, Inc. BHE BH Electronics BHR Bahr Technologies, Inc. BLB Bay Laboratories BME Bartel Marine Electronics BNI Neil Brown Instrument Systems BNS Bowditch Navigation Systems BRM Mel Barr Company BRY Byrd Industries BTH Benthos, Inc. BTK Baltek Corporation BTS Boat Sentry, Inc. BXA Bendix-Avalex, Inc. CAT Catel CBN Cybernet Marine Products CCA Copal Corporation of America CCC Coastal Communications Company CCL Coastal Climate Company CCM Coastal Communications CDC Cordic Company CEC Ceco Communications, Inc. CHI Charles Industries, Limited CKM Cinkel Marine Electronics Industries CMA Societe Nouvelle D’Equiment du Calvados CMC Coe Manufacturing Company CME Cushman Electronics, Inc. CMP C-Map, s.r.l. CMS Coastal Marine Sales Company CMV CourseMaster USA, Inc. CNV Coastal Navigator CNX Cynex Manufactoring Company CPL Computrol, Inc. CPN Compunav CPS Columbus Positioning, Inc. CPT CPT, Inc. CRE Crystal Electronics, Limited CRO The Caro Group CRY Crystek Crystals Corporation CSI Communication Systems International, Inc. CSM Comsat Maritime Services CST Cast, Inc. CSV Combined Services CTA Current Alternatives CTB Cetec Benmar CTC Cell-tech Communications CTE Castle Electronics CTL C-Tech, Limited CNI Continental Instruments CWD Cubic Western Data CWV Celwave R.F., Inc. CYZ cYz, Inc. DCC Dolphin Components Corporation DEB Debeg GmbH DFI Defender Industries, Inc. DGC Digicourse, Inc. DME Digital Marine Electronics Corp. DMI Datamarine International, Inc. DNS Dornier System GmbH DNT Del Norte Technology, Inc. DPS Danaplus, Inc. DRL R.L. Drake Company DSC Dynascan Corporation DYN Dynamote Corporation DYT Dytek Laboratories, Inc. EBC Emergency Beacon Corporation ECT Echotec, Inc. EEV EEV, Inc. EFC Efcom Communication Systems ELD Electronic Devices, Inc. EMC Electric Motion Company EMS Electro Marine Systems, Inc. ENA Energy Analysts, Inc. ENC Encron, Inc. EPM Epsco Marine EPT Eastprint, Inc. ERC The Ericsson Corporation ESA European Space Agency FDN Fluiddyne FHE Fish Hawk Electronics FJN Jon Fluke Company FMM First Mate Marine Autopilots FNT Franklin Net and Twine, Limited FRC The Fredericks Company FTG T.G. Faria Corporation FUJ Fujitsu Ten Corporation of America FEC Furuno Electric Company (??)

FUR Furuno USA, Inc. GAM GRE America, Inc. GCA Gulf Cellular Associates GES Geostar Corporation GFC Graphic Controls Corporation GIS Galax Integrated Systems GPI Global Positioning Instrument Corporation GRM Garmin Corporation GSC Gold Star Company, Limited GTO Gro Electronics GVE Guest Corporation GVT Great Valley Technology HAL HAL Communications Corporation HAR Harris Corporation HIG Hy-Gain HIT Hi-Tec HPK Hewlett-Packard HRC Harco Manufacturing Company HRT Hart Systems, Inc. HTI Heart Interface, Inc. HUL Hull Electronics Company HWM Honeywell Marine Systems ICO Icom of America, Inc. IFD International Fishing Devices IFI Instruments for Industry IME Imperial Marine Equipment IMI I.M.I. IMM ITT MacKay Marine IMP Impulse Manufacturing, Inc. IMT International Marketing and Trading, Inc. INM Inmar Electronic and Sales, Inc. INT Intech, Inc. IRT Intera Technologies, Ltd. IST Innerspace Technology, Inc. ITM Intermarine Electronics, Inc. ITR Itera, Limited JAN Jan Crystals JFR Ray Jefferson JMT Japan Marine Telecommunications JRC Japan Radio Company, Inc. JRI J-R Industries, Inc. JTC J-Tech Associates, Inc. JTR Jotron Radiosearch, Ltd. KBE KB Electronics, Ld. KBM Kennebec Marine Company KLA Klein Associates, Inc. KMR King Marine Radio Corporation KNG King Radio Corporation KOD Koden Electronics Company, Ltd. KRP Krupp International, Inc. KVH KVH Company KYI Kyocera International, Inc. LAT Latitude Corporation LEC Lorain Electronics Corporation LMM Lamarche Manufacturing Company LRD Lorad LSE Littlemore Scientific Engineering LSP Laser Plot, Inc. LTF Littlefuse, Inc. LWR Lowrance Electronics Corportation MCL Micrologic, Inc. MDL Medallion Instruments, Inc. MEC Marine Engine Center, Inc. MEG Maritec Engineering GmbH MFR Modern Products, Ltd MFW Frank W. Murphy Manufacturing MGN Magellan Corporation MGS MG Electronic Sales Corporation MIE Mieco, Inc. MIM Marconi International Marine Company MLE Martha Lake Electronics MLN Matlin Company MLP Marlin Products MLT Miller Technologies MMB Marsh-McBirney, Inc. MME Marks Marine Engineering MMP Metal Marine Pilot, Inc. MMS Mars Marine Systems MNI Micro-Now Instrument Company MNT Marine Technology MNX Marinex MOT Motorola MPN Memphis Net and Twine Company, Inc. MQS Marquis Industries, Inc. MRC Marinecomp, Inc. MRE Morad Electronics Corporation MRP Mooring Products of New England MRR II Morrow, Inc. MRS Marine Radio Service MSB Mitsubishi Electric Company, Ltd. MSE Master Electronics MSM Master Mariner, Inc. MST Mesotech Systems, Ltd. MTA Marine Technical Associates MTG Narine Technical Assistance Group MTK Martech, Inc. MTR Mitre Corporation, Inc. MTS Mets, Inc. MUR Murata Erie North America MVX Magnavox Advanced Products and Systems Company MXX Maxxima Marine MES Marine Electronics Service, Inc. NAT Nautech, Limited NEF New England Fishing Gear, Inc. NMR Newmar NGS Navigation Sciences, Inc. NOM Nav-Com, Inc. NOV NovAtel Communications, Ltd. NSM Northstar Marine NTK Novatech Designs, Ltd. NVC Navico NVS Navstar NVO Navionics, s.p.a. OAR O.A.R. Corporation ODE Ocean Data Equipment Corporation ODN Odin Electronics, Inc. OIN Ocean instruments, Inc. OKI Oki Electronic Industry Company OLY Navstar Limited (Polytechnic Electronics) OMN Omnetics ORE Ocean Research

OTK Ocean Technology PCE Pace PDM Prodelco Marine Systems PLA Plath, C. Division of Litton PLI Pilot Instruments PMI Pernicka Marine Products PMP Pacific Marine Products PRK Perko, Inc. PSM Pearce-Simpson PTC Petro-Com PTG P.T.I./Guest PTH Pathcom, Inc. RAC Racal Marine, Inc. RAE RCA Astro-Electronics RAY Raytheon Marine Company RCA RCA Service Company RCH Roach Engineering RCI Rochester Instruments, Inc. RDI Radar Devices RDM Ray-Dar Manufacturing Company REC Ross Engineering Company RFP Rolfite Products, Inc. RGC RCS Global Communications, Inc. RGY Regency Electronics, Inc. RMR RCA Missile and Surface Radar RSL Ross Laboratories, Inc. RSM Robertson-Shipmate, USA RWI Rockwell International RME Racal Marine Electronics RTN Robertson Tritech Nyaskaien A/S SAI SAIT, Inc. SBR Sea-Bird electronics, Inc. SCR Signalcrafters, Inc. SEA SEA SEC Sercel Electronics of Canada SEP Steel and Engine Products, Inc. SFN Seafarer Navigation International SGC SGC, Inc. SIG Signet, Inc. SIM Simrad,Inc SKA Skantek Corporation SKP Skipper Electronics A/S SLI Starlink, Inc. SME Shakespeare Marine Electronics SMF Seattle Marine and Fishing Supply Co. SML Simerl Instruments SMI Sperry Marine, Inc. SNV Starnav Corporation SOM Sound Marine Electronics, Inc. SOV Sell Overseas America SPL Spelmar SPT Sound Powered Telephone SRD SRD Labs SRS Scientific Radio Systems, Inc. SRT Standard Radio and Telefon AB SSI Sea Scout Industries STC Standard Communications STI Sea-Temp Instrument Corporation STM Si-Tex Marine Electronics SVY Savoy Electronics SWI Swoffer Marine Instruments, Inc. SRS Shipmate, Rauff & Sorensen, A/S TBB Thompson Brothers Boat Manufacturing Company TCN Trade Commission of Norway (THE) TDL Tideland Signal THR Thrane and Thrane A/A TLS Telesystems TMT Tamtech, Ltd. TNL Trimble Navigation TRC Tracor, Inc. TSI Techsonic Industries, Inc. TTK Talon Technology Corporation TTS Transtector Systems TWC Transworld Communications, Inc. TXI Texas Instruments, Inc. UME Umec UNI Uniden Corporation of America UNP Unipas, Inc. UNF Uniforce Electronics Company VAN Vanner, Inc. VAR Varian Eimac Associates VCM Videocom VEX Vexillar VIS Vessel Information Systems, Inc. VMR Vast Marketing Corporation WAL Walport USA WBG Westberg Manufacturing, Inc. WEC Westinghouse Electric Corporation WHA W-H Autopilots WMM Wait Manufacturing and Marine Sales Company WMR Wesmar Electronics WNG Winegard Company WSE Wilson Electronics Corporation WTC Watercom WST West Electronics Ltd. YAS Yaesu Electronics

8. References [1] National Marine Electronics Association: http://www.nmea.org [2] Torsten Baumbach’s web site: http://pandora.inf.uni-jena.de/ttbb/ [3] Peter Bennett’s GPS and NMEA site: http://vancouver-webpages.com/pub/peter/index.html [4] Data Transmission Protocol Specification for Magellan Products. Revision 1.0. Magellan Corporation, Santa Clara 1999. Available at: http://magellangps.com This document describes the protocol used by Magellan’s consumer GPS units, including a number of NMEA 0183 proprietary sentences. [5] SBA-1 Interfacing Manual. Revision 0.0. Communications Systems International, Inc, Calgary, 1999. Available at: www.csi-dgps.com. This manual explains the interfacing of the SBA-1 DGPS beacon receiver to numerous GPS units as well as the CSI proprietary sentences used.