iSXblue/SXBlue II GNSS Series Technical Reference Manual
122
5.9.9
VTG Data Message
The VTG message contains velocity and course information. The table below breaks down the VTG data
message into its components. This message has the following format:
$GPVTG,ttt,c,ttt,c,ggg.gg,u,ggg,gg,u*cc<CR><LF>
Table 5-20 VTG Data Message Defined
Field
Description
Ttt
True course over ground, ttt = 000 to 359, in degrees
C
True course over ground indicator, c = T always
Ttt
Magnetic course over ground, ttt = 000 to 359, in degrees
C
Magnetic course over ground Indicator, always c = M
ggg.gg
Speed over ground, 000 to 999 knots
U
Speed over ground units, u = N = Nautical mile/h
ggg.gg
Speed over ground, 000 to 999 km/h
U
Speed over ground units, u = K = kilometer/h
*cc
Checksum
<CR><LF>
Carriage return and line feed
5.9.10
ZDA Data Message
The ZDA message contains Universal Time information. The table below breaks down the ZDA data
message into its components. This message has the following format:
$GPZDA,hhmmss.ss,dd,mm,yyyy,xx,yy*cc<CR><LF>
Table 5-21 ZDA Data Message Defined
Field
Description
hhmmss.ss
UTC time in hours, minutes, seconds of the GPS position
dd
Day, dd = 0 to 31
mm
Month, mm = 1 to 12
yyyy
Year
xx
Local zone description in hours, xx = -13 to 13
yy
Local zone description in minutes, yy = 0 to 59
*cc
Checksum
<CR><LF>
Carriage return and line feed
5.9.11
GRS Data Message
The GRS message supports the Receiver Autonomous Integrity Monitoring (RAIM).The GRS data
message is broken down into its components in the table below. This message takes the following form:
$--GRS.hhmmss.ss,y,x.x,x.x,x.x,x.x,x.x,x.x,x.x,x.x,x.x,x.x,x.x,x.x*hh<CR><LF>