Installation Manual

AIS Installation Manual Issue 1 35
7.4.12 GLL – geographic position
This sentence is a primary source of position information for the transponder when connected to
a functional GNSS system. In the absence of GNS sentences, longitude and latitude information
may also be obtained from GNS, GGA or RMC sentences.
$--GLL,llll.ll,a,yyyyy.yy,a,hhmmss.ss,A,a*hh<CR><LF>
mode indicator (‘A’, ‘D’, ‘E’, ‘M’ -> used; ‘N’ -> invalid)
status (‘A’ -> use mode flag; ‘V’ -> use position as default)
UTC of position
longitude, E/W
latitude, N/S
Note that DTM sentences must be received by the transponder at least once every 30 seconds
in order for the GLL sentence to be accepted.
7.4.13 GNS – GNSS fix data
The transponder may receive this sentence from other sensors and uses the information in its
own calculations of the ship’s current position.
$--GNS,hhmmss.ss,llll.ll,a,yyyyy.yy,a,c—c,xx,x.x,x.x,x.x,x.x,x.x*hh<CR><LF>
Diff ref erence station ID (ignored)
age of diff data (ignored)
geoidal separation (ignored)
antenna altitude (ignored)
HDOP (ignored)
number of satellites in use (ignored)
mode indicator (‘A’, D’, ‘E’, ‘M’ - used; ‘N’ - default value)
longitude, E/W
latitude, N/S
UTC of position
7.4.14 HDT – heading true
This sentence provides the actual vessel heading and may be sent by any system or device that
calculates true headings.
$--HDT,x.x,T*hh<CR><LF>
heading, degrees true
7.4.15 LR1 - AIS long-range reply 1
The LR1 sentence identifies the destination for the reply and contains the information items
requested by the function identification character in the LRF sentence that requested the
information.
$--LR1,x,xxxxxxxxx,xxxxxxxxx,c—c,c—c,xxxxxxxxx*hh<CR><LF>
IMO number
call sign
ship’s name
MMSI of requestor (reply
destination)
MMSI of responder
sequence number