Et-312 – USGlobalsat ET-312 User Manual
Page 13
ET-312
The Specifications are subject to be changed without notice. Copyright © 2007, GlobalSat Technology.
Page 13 of 21
Version 1.4
VTG-Course Over Ground and Ground Speed
$GPVTG,309.62,T,,M,0.13,N,0.2,K*6E
Name Example Units
Description
Message ID
$GPVTG
VTG protocol header
Course 309.62
degrees
Measured heading
Reference T
True
Course
degrees
Measured heading
Reference
M
Magnetic
Speed 0.13
knots
Measured
horizontal
speed
Units
N
Knots
Speed 0.2
Km/hr
Measured horizontal speed
Units K
Kilometers
per hour
Checksum *6E
<CR><LF>
End
of
message termination
2.2 NMEA Input Command
A)
. Set Serial Port
ID:100 Set PORTA parameters and protocol
This command message is used to set the protocol(SiRF Binary, NMEA, or USER1) and/or the
communication parameters(baud, data bits, stop bits, parity). Generally,this command would be used to
switch the module back to SiRF Binary protocol mode where a more extensive command message set is
available. For example,to change navigation parameters. When a valid message is received,the parameters
will be stored in battery backed SRAM and then the receiver will restart using the saved parameters.
Format:
$PSRF100,<protocol>,<baud>,<DataBits>,<StopBits>,<Parity>*CKSUM
<CR><LF>
<protocol> 0=SiRF Binary, 1=NMEA, 4=USER1
<baud>
1200, 2400, 4800, 9600, 19200, 38400
<DataBits> 8,7. Note that SiRF protocol is only valid f8 Data bits
<StopBits> 0,1