Tritech MicronNav - Page 122

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 Return + 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).