Format of the nmea 0183 string (rmc) – Meinberg GPS170LCD-MP User Manual
Page 47
47
Format of the NMEA 0183 String (RMC)
The NMEA String is a sequence of 65 ASCII characters starting with the ‘$’ character
and ending with the characters CR (carriage return) and LF (line-feed). The format is:
$GPRMC,hhmmss.ss,A,bbbb.bb,n,lllll.ll,e,0.0,0.0,ddmmyy,0.0,a*hh
The letters printed in italics are replaced by ASCII numbers or letters whereas the
other characters are part of the time string. The groups of characters as defined below:
$
Start character, ASCII Code 24h
sending with one bit occuracy at change of second
hhmmss.ss
the current time:
hh
hours
(00..23)
mm minutes
(00..59)
ss
seconds
(00..59, or 60 while leap second)
ss
fractions of seconds (1/10 ; 1/100)
A
Status
(A = time data valid)
(V = time data not valid)
bbbb.bb
latitude of receiver position in degrees
leading signs are replaced by a space character (20h)
n
latitude, the following characters are possible:
‘N’ north of equator
‘S’ south d. equator
lllll.ll
longitude of receiver position in degrees
leading signs are replaced by a space character (20h)
e
longitude, the following characters are possible:
‘E’ east of Greenwich
‘W’ west of Greenwich
ddmmyy
the current date:
dd
day of month
(01..31)
mm month
(01..12)
yy
year of the century
(00..99)
a
magnetic variation
hh
checksum (EXOR over all characters except ‘$’ and ‘*’)
Carriage Return, ASCII Code 0Dh
Line Feed, ASCII Code 0Ah