Linx Technologies RXM-GPS-R4 - Manual (Page 12)

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100 – SetSerialPort
This command message is used to set the protocol (SiRF binary or NMEA)
and/or the communication parameters (baud rate). Generally, this
command is used to switch the module back to SiRF binary protocol mode
where a more extensive command message set is available. When a valid
message is received, the parameters are stored in battery-backed SRAM
and the receiver restarts using the saved parameters.
Figure 18 contains the values for the following example:
Switch to SiRF binary protocol at 9600,8,N,1
$PSRF100,0,9600,8,1,0*0C
For details on the SiRF binary protocol, please refer to SiRF’s Binary
Protocol Reference Manual.
SetSerialPort Example
Name Example Description
Message ID $PSRF100 PSRF100 protocol header
Protocol 0 0=SiRF binary, 1=NMEA
Baud 9600 4800, 9600, 19200, 38400, 57600, 115200
DataBits 8 8 1
StopBits 1 0, 1 1
Parity 0 0=None, 1=Odd, 2=Even 1
Checksum *0C
<CR> <LF> End of message termination
1. SiRF protocol is only valid for 8 data bits, 1 stop bit and no parity.
2. Default settings are NMEA protocol using 9,600 baud, 8 data bits, 2 stop bits and no
parity.
Figure 18: SetSerialPort Example
101 – NavigationInitialization
This command is used to initialize the receiver with the current position (in
X, Y, Z 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.
Figure 19 contains the values for the following example:
$PSRF101,-2686700,-4304200,3851624,96000,497260,921,12,3*1C
Figure 19: NavigationInitialization Example
NavigationInitialization Example
Name Example Units Description
Message ID $PSRF101 PSRF101 protocol header
ECEF X -2686700 meters X coordinate position
ECEF Y -4304200 meters Y coordinate position
ECEF Z 3851624 meters Z coordinate position
ClkOffset 96000 Hz Clock Offset 1
TimeOfWeek 497260 seconds GPS Time Of Week
WeekNo 921 GPS Week Number
ChannelCount 12 Range 1 to 12
ResetCfg 3 See Figure 20
Checksum *1F
<CR> <LF> End of message termination
1. Use 0 for the last saved value if available. If this is unavailable, a default value of
96000 is used.
ResetCfg Values
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 the receiver
back to factory defaults
Figure 20: ResetCfg Values