Garmin TracPak GPS 30/30 SL Manual page 29

010190
If a negative leap second should be required, one second
will be deleted at the end of some UTC month. The minute
containing the leap second will be only 59 seconds long. In
this case, the GPS 30/30 SL will not transmit the time of day
23h 59m 59s for the day from which the leap second is
removed.
4.2.3 Global Positioning System Almanac Data
(ALM)
(GPS 30 Rev. 1.30 or later and all GPS 30 SL revs)
$GPALM,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,
<12>,<13>,<14>,<15>*hh<CR><LF>
Almanac sentences are not normally transmitted. Almanac
transmission can be initiated by sending the sensor board
a $PGRMO,GPALM,1 command. Upon receipt of this
command, the sensor board will transmit available almanac
information on GPALM sentences. During the transmission
of almanac sentences other NMEA data output will be
temporarily suspended.
<field information> can be found in section 4.1.1.
4.2.4 Global Positioning System Fix Data (GGA)
$GPGGA,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,M,<10>,
M,<11>,<12>*hh<CR><LF>
<1> UTC time of position fix, hhmmss format
<2> Latitude, ddmm.mmmm format (leading zeros will
be transmitted)
<3> Latitude hemisphere, N or S
<4> Longitude, dddmm.mmmm format (leading zeros
will be transmitted)
<5> Longitude hemisphere, E or W
<6> GPS quality indication, 0 = fix not available, 1 =
000000
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