User`s guide

Chapter 5 - I/O Commands
Motorola GPS Products - M12+ User's Guide Revision 6.X 09FEB05
191
GPVTG (TRACK MADE GOOD AND GROUND SPEED)
NMEA-0183 Format
Set message output rate:
$PMOTG, VTG, yyyy*CC<CR><LF>
where:
yyyy = update rate 0000 .. 9999 seconds
CC = optional checksum
Note - the asterisk (*) is not present unless the optional checksum is present
Response to above command:
$GPVTG, a.a, b, c.c, d, e.e, f, g.g, h*CC<CR><LF>
where:
a.a = Track (degrees true)
b = T (message formatting constant)
c.c = Track (degrees magnetic) ** always nulled with M12+
d = M (message formatting constant)
e.e = speed in knots
f = N (message formatting constant)
g.g = speed in km/hr
h = K (message formatting constant
CC checksum