Using the External Computer Data Link
MicronNav System
0656-SOM-00001-07
122
© Tritech International Ltd.
‘$GPRMC’ Reply Data Structure
Data Description
Data Range
Field Range
Comma separator
Always ‘,’
,
Time of data, UTC = hhmmss.ss
000000.00 to 235959.99
hhmmss.ss
Comma separator
Always ‘,’
,
Fix Status (N.B. Invalid if Ping not okay or
no valid attitude or compass data)
‘A’ = Valid, ‘V’ = Invalid
x
Comma separator
Always ‘,’
,
Latitude of Target in Deg Min (Only valid
when Compass and GPS input data are
valid)
0 to 90 Degs
DDMM.SSSS
Comma separator
Always ‘,’
,
Latitude N or S
‘N’ or ‘S’
a
Comma separator
Always ‘,’
,
Longitude of Target in Deg Min (Only valid
when Compass and GPS input data are
valid)
0 to 180 Degs
DDDMM.SSSS
Comma separator
Always ‘,’
,
Longitude E or W
‘E’ or ‘W’
a
Comma separator
Always ‘,’
,
Speed Over Ground (in knots)
Not calculated, always 0.00 x.xx
Comma separator
Always ‘,’
,
Course Over Ground (in degrees)
Not calculated, always
000.00
xxx.xx
Date of data
Gregorian calendar 010100
to 311299
ddmmyy
Comma separator
Always ‘,’
,
Magnetic Variation
N/A, always ‘‘
x
Comma separator
Always ‘,’
,
Delimiter (asterisk)
Always ‘*’
*
Checksum (in Hexadecimal)
(XOR of bytes between, but not inclusive
of, '$' and '*')
00 to FF
cc
(Carriage Line Feed)
N/A
<CR><LF>
Example:
Target Latitude = 54º 22’ 22.30” (N), Target Longitude = 2º 56’ 25.51” (W), UTC Time of reading =
143221.57, Date of reading = 9th May 2008.
ASCII Output Always (on a single line) =
“$GPRMC,143221.57,A,5422.3717,N,00256.4252,W, 0.00,000.00,090508,,*0F<CR><LF>”
Where; “<CR>” is Carriage Return (ASCII code 13), “<LF>” is Line Feed (ASCII code 10).