Furuno Sc 50 - Manual (Page 71)

APPENDIX
AP-5
GNS - GNNS fix data
$--GNS,hhmmss.ss,llll.lll,a,yyyyy.yyy,a,c--c,xx,x.x,x.x,x.x,x.x,x.x*hh
| | | | | | | | | | | | |
| | | | | | | | | | | | +--- 11
| | | | | | | | | | | +------ 10
| | | | | | | | | | +---------- 9
| | | | | | | | | +-------------- 8
| | | | | | | | +------------------ 7
| | | | | | | +---------------------- 6
| | | | | | +------------------------- 5
| | | | | +------------------------------ 4
| | | +-------+--------------------------------- 3
| +---+--------------------------------------------- 2
+------------------------------------------------------------- 1
1. UTC of position
2. Latitude, N/S
3. Longitude, E/W
4. Mode indicator
5. Total number of satllite in use,00-99
6. HDOP
7. Antenna altitude, metres, re:mean-sea-level(geoid)
8. Geoidal separation
9. Age of differential data
10. Differential reference station ID
11. Checksum
HDM- Heading – magnetic
This sentence is not used in the current version of NMEA and IEC 61162. Some boaters may want the
GPS compass to indicate the magnetic heading when the boat is only fitted with a magnetic compass.
HDG is calculated by adding a geomagnetic variation to HDT.
$--HDM, x.x, M *hh
Heading, degrees true
HDT - Heading - true
True heading in degrees obtained by processing RF cycle in the GPS carrier frequency.
$--HDT, x.x, T*hh
Heading, degrees true
ROT – Rate of turn
ROT derived from a changing rate of GPS compass heading.
$--ROT, x.x, A*hh
Status: A = data valid
Rate of turn, degrees/min, “-” = bow turns to port