iSXblue/SXBlue II GNSS Series Technical Reference Manual
94
Table 5-5 DGPS Beacon Commands
Message
Description
Type
$GPMSK
Command to tune beacon receiver and turn on diagnostic information
Proprietary
$PCSI,1
$PCSI,2
These commands are used to get beacon status information from channel #0 and
channel #1
Proprietary
$PCSI,3,2
Command to list the 10 closest stations
Proprietary
$PCSI,3,3
Command to display the contents of the internal station database
Proprietary
$PCSI,0
Receiver Help Query. Lists available $PCSI commands
Proprietary
$PCSI,8,NITRAM
Advanced configuration settings
Proprietary
$GPCRQ,MSK
Standard NMEA query to prompt receiver for Operational Status
Standard
$GPCRQ,MSS
Standard NMEA query to prompt receiver for Performance Status
Standard
5.4.1
$GPMSK
$GPMSK is the Beacon Tune command. This command instructs the SXBlue II-B GPS to tune to a
specified frequency and automatically select the correct MSK rate. The resulting confirmation of this
message will be returned to the same port from which the command was sent. It has the following form:
$GPMSK,fff.f,F,mmm,M,n<CR><LF
($GPMSK in Capital letters)
Response:
$PCSI,ACK,GPMSK,fff.f,F,mmm,M,n<CR><LF>
If using Database (D) or Automatic (A) tuning mode the command has the following form:
$GPMSK,,D,,D<CR><LF> or $GPMSK,,A,,A<CR><LF>
Data Field
Description
fff.f
This field is the beacon frequency in kHz (283.5 to 325) and
may be left null if the following field is set to automatic “A” or
Database “D”
F
This field selects the frequency selection mode, either Manual “M”
or Automatic “A” or Database “D”
mmm
This field is the MSK bit rate. If the following field is set to
Automatic “A” or Database “D,” this field can be left null.
M
This field selects the MSK rate selection mode, either Manual “M” or
Automatic “A” or Database “D"“
n
Period of output of performance status message 0 to 100 seconds
($CRMSS)
When this message is acknowledged by the SXBlue II-B GPS, it will immediately tune to the frequency
specified and demodulate at the rate specified. When the “n” field is set to a non-zero value, the SXBlue
II-B GPS will output the $CRMSS message at that period through the communication port from which
the SXBlue II-B GPS was tuned. When issuing the tune command with a nonzero “n” field, the periodic
output of the $CRMSS message will not impact the current output of messages. However, when tuning
the SXBlue II-B GPS with a non-zero “n” field, the $CRMSS status message will be interspersed within
the preset messages on the current communication port. Most GPS software will not be able to filter the
NMEA 0183 messages, causing the overall data to fail parity checking. When power to the SXBlue II-B
GPS is removed and reapplied, the status output interval resets to zero (no output).