iSXblue/SXBlue II GNSS Series Technical Reference Manual
86
Table 5-3 GPS Commands
Message
Description
$JASC
This command is used to configure the NMEA message output of the GPS engine
$JAGE
This command is used to configure the maximum age of DGPS corrections
$JOFF
This command is used to turn off all data output by the GPS engine
$JMASK
This command allows you to modify the cut-off angle for tracking of GPS satellites
$JNP
This command allows to set the number of decimal digits in the GGA and GLL
output messages
$J4STRING
This command allows you to configure the GPS for output of the GPGGA, GPGSA,
GPVTG, and GPZDA messages at a specific baud rate
$JSMOOTH
This command allows changes in the carrier phase smoothing interval
$JTAU
Time constants to adjust level of responsiveness of SPEED and COG
The following subsections provide detailed information relating to the use of each command.
Note - Please ensure that you save any changes that you wish to survive beyond the current power-
up by using the $JSAVE command and wait for the ‘
$> Save Complete’
response.
5.2.26
$JASC
Using this command, you may turn GPS data messages on at a particular update rate or off. When
turning messages on, you have the choice of various update rates available, depending on what your
requirements are.
This command has the following layout:
$JASC,msg,r[,PORTy]<CR><LF>
Where ‘msg’ is the name of the data message and ‘r’ is the message rate, as shown in the table below.
Sending the command without the optional [,PORTy] data field (without the square brackets) will enact a
change on the current port.
A message is turned off by sending a command with a zero value for the ‘r’ field.
msg
r (Hz)
Description
GPGBS
20, 10, 2, 1, 0 or .2
Satellite Fault Detection (used for RAIM)
GPGGA
20, 10, 2, 1, 0 or .2
Global Positioning System Fix Data
GPGLL
20, 10, 2, 1, 0 or .2
Geographic Position – Latitude/Longitude
GPGNS
20, 10, 2, 1, 0 or .2
GNSS (Global Navigation Satellite System) fix data
GPGRS
20, 10, 2, 1, 0 or .2
GNSS Range Residuals
GPGSA
1 or 0
GNSS DOP and Active Satellites
GPGST
1 or 0
GNSS Pseudorange Error Statistics
GPGSV
1 or 0
GNSS Satellites in View
GPRMC
10, 2, 1, 0 or .2
Recommended Minimum Specific GNSS Data
GPRRE
1 or 0
Range residual message
GPVTG
10, 2, 1, 0 or .2
Course Over Ground and Ground Speed
GPZDA
10, 2, 1, 0 or .2
Time and Date
When the ‘,PORTy’ data field is specified (without the square brackets and where ‘y’ is A, B or C), this
command will enact a change in the $GPmsg message on the Bluetooth, Serial or USB port.