Professor Tech RGM-3000 Series - Manual (Page 21)

Professor RGM-3000/REB-3000
GPS Module Operational Manual)
20
Table 6 RMC Data Format
Name Example Units Description
Message ID $GPRMC RMC protocol header
UTC Position 161229.487 hhmmss.sss
Status A A=data valid or V=data not valid
Latitude 3723.2475 ddmm.mmmm
N/S Indicator N N=north or S=south
Longitude 12158.3416 dddmm.mmmm
E/W Indicator W E=east or W=west
Speed Over Ground 0.13 knots
Course Over Ground 309.62 degrees True
Date 120598 ddmmyy
Magnetic Variation degrees E=east or W=west
Checksum *10
ҦCRҨҦLFҨ End of message termination
VTG-Course Over Ground and
Ground Speed
Table 7 contains the values of the following
example:$GPVTG, 309.62, T, , M, 0.13, N,
0.2, K*6E
Table 7 VTG Data Format
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 Kilometer per hour
Checksum *6E
ҦCRҨҦLFҨ End of message termination
.
GPS Receiver User’s Tip
1. GPS signal will be affected by weather and environment conditions, thus suggest to use the GPS
receiver under less shielding environments to ensure GPS receiver has better receiving performance.
2. When GPS receiver is moving, it will prolong the time to fix the position, so suggest to wait for the
satellite signals to be locked at a fixed point when first power-on the GPS receiver to ensure to lock
the GPS signal at the shortest time.
3. The following situation will affect the GPS receiving performance:
a. Solar control filmed windows.
b. Metal shielded, such as umbrella, or in vehicle.
c. Among high buildings.
d. Under bridges or tunnels.
e. Under high voltage cables or near by radio wave sources, such as mobile phone base
stations.
f. Bad or heavy cloudy weather.
4. If the satellite signals can not be locked or encounter receiving problem (while in the urban area), the
following steps are suggested:
a. Please plug the external active antenna into GPS receiver and put the antenna on outdoor or the
roof of the vehicle for better receiving performance.
b. Move to another open space or reposition GPS receiver toward the direction with less blockage.
c. Move the GPS receiver away from the interferences resources.
d. Wait until the weather condition is improved.