Airmar LB150 - Manual (Page 51)

LB150 WeatherStation Technical Manual revision 0.013
Proprietary and Confidential
PRELIMINARY - DRAFT 48
_ NMEA 0183 RECEIVED SENTENCE _
$PAMTC,
DATUM
Summary
Define the local datum to which GPS position locations are referenced.
Syntax
One of the following forms:
$PAMTC,DATUM,SET,<3>,<4>*hh
$PAMTC,DATUM,Q*hh
Fields
<3> Three character alphabetical code for local datum:
W84 (WGS84)
W72 (WGS72)
S85 (SGS85)
P90 (PE90)
or IHO datum code from the International Hydrographic
Organization Publication S-60 Appendices B and C.
<4> One character subdivision datum code when available, as defined in
IHO Publication S-60 Appendices B and C.
Notes
The $PAMTC,DATUM,SET,<3>,<4> command is used to establish the local
datum used by the GPS receiver for calculating position. These values are stored
in EEPROM memory within the unit. The default value for field <3> is W84
(WGS84). The default value for field <4> is a null field (no subdivision datum
code).
Unlike other NMEA 0183 proprietary commands, if in the command
$PAMTC,DATUM,SET,<3>,<4> field <4> is a null field, the value will be
actually set to null (no subdivision datum code).
The $PAMTC,DATUM,Q command may be used to determine the current datum
setting within the unit. Upon receiving this command, the unit will reply with
$PAMTR,DATUM,<3>,<4>, where fields <3> and <4> are as described above.
The value established by this command will be used by the transmitted $GPDTM
sentence.