Linx Technologies RXM-GPS-SR - Manual (Page 9)

Page 17 Page 16
103 – Query/Rate Control
This command is used to control the output of standard NMEA messages GGA,
GLL, GSA, GSV, RMC, and VTG. Using this command message, standard
NMEA messages may be polled once, or setup for periodic output. Checksums
may also be enabled or disabled depending on the needs of the receiving
program. NMEA message settings are saved in battery-backed memory for each
entry when the message is accepted.
The table below contains the values for the following example:
1. Query the GGA message with checksum enabled
$PSRF103,00,01,00,01*25
2. Enable VTG message for a 1 Hz constant output with checksum enabled
$PSRF103,05,00,01,01*20
3. Disable VTG message
$PSRF103,05,00,00,01*21
Name Example Units Description
Message ID $PSRF103 PSRF103 protocol header
Msg 0 See Table 17
Mode 1 0=SetRate, 1=Query
Rate 0 seconds Output – off=0, max=255
CksumEnable 1 0=Disable, 1=Enable Checksum
Checksum *25
End of message termination
Value Description
0 GGA
1 GLL
2 GSA
3 GSV
4 RMC
5 VTG
6 MSS (Not Supported)
7 Not defined
8 ZDA
9 Not defined
Table 15: Query/Rate Control Example
Table 16: MSG Values
104 – LLANavigationInitialization
This command was used to initialize the receiver with the current position (in
lattitude, longitude and altitude coordinates), clock offset, and time, enabling a
faster fix. Increased receiver sensitivity and the removal of Selective Availability
(SA) have made this unneccessary. The command is retained for its ability to
reset the module, but the initialization fields are no longer supported.
The table below contains the values for the following example:
$PSRF104,0,0,0,96000,0,0,12,4*1A
Name Example Units Description
Message ID $PSRF104 PSRF104 protocol header
Latitude 0
Longitude 0
Altitude 0
ClkOffset 96000
TimeOfWeek 0
WeekNo 0
ChannelCount 12
ResetCfg 4 See Table 19
Checksum *1A
End of message termination
Hex Description
0x01 Hot Start – All data valid
0x02 Warm Start – Ephemeris cleared
0x04 Cold Start – Clears all data in memory
0x08
Clear Memory – Clears all data in memory and resets receiver back to
factory defaults
Table 17: LLANavigationInitialization Example
Table 18: ResetCfg Values