Specifications

Command/Response Formats 183
Commands
Example: Send VTG message to port C
$PASHQ,VTG,C <enter>
$GPVTG
The response message is in the form:
$GPVTG,f1,T,f2,M,f3,N,f4,K*cc <enter>
Example:
Query: $PASHQ,VTG <enter>
Response: $GPVTG,004.58,T,349.17,M,000.87,N,001.61,K*46 <enter>
Table 6.120 on page 183 describes each item in a typical VTG message.
Table 6.119: VTG Message Structure
Parameters Description Range
f1 COG (Course Over Ground) true north 0 - 359.99
T COG orientation (T = true north) T
f2 COG magnetic north 0 - 359.99
M COG orientation (M = magnetic north) M
f3 SOG (Speed Over Ground) 0 - 999.99
N SOG units (N = knots) N
f4 SOG (Speed Over Ground) 0 - 999.99
K SOG units (K = Km/hr) K
*cc checksum
Table 6.120: Typical VTG Message
Item Significance
$GPVTG Header
004.58 Course Over Ground (COG) oriented to true north
T True North orientation
349.17 Course Over Ground (COG) oriented to magnetic north
M Magnetic north orientation
000.87 Speed Over Ground (SOG) in knots
N SOG units (N=knots)