Garmin DGPS 53, Руководство пользователя

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12
Operation
Using the
DGPS 53
Sensor Initialization Information (PGRMI)
The $PGRMI sentence provides information used to initialize the position and time used for satellite
acquisition. Receipt of this sentence by the DGPS 53 causes the software to restart the satellite
acquisition process. If there are no errors in the sentence, it will be echoed upon receipt. If an error
is detected, the echoed PGRMI sentence will contain the current default values. Current PGRMI
defaults can also be obtained by sending “$PGRMIE” to the board.
$PGRMI,<1>,<2>,<3>,<4>,<5>,<6>,<7>*hh<CR><LF>
<1> Latitude, ddmm.mmm format (leading zeros must be transmitted)
<2> Latitude hemisphere, N or S
<3> Longitude, dddmm.mmm format (leading zeros must be transmitted)
<4> Longitude hemisphere, E or W
<5> Current UTC date, ddmmyy format
<6> Current UTC time, hhmmss format
<7> Receiver Command, A = Auto Locate, R = Unit Reset
Sensor Configuration Information (PGRMC)
The $PGRMC sentence provides information used to configure the DGPS53. Configuration
parameters are stored in non-volatile memory and retained between power cycles. The DGPS 53 will
echo this sentence upon its receipt if no errors are detected. If an error is detected, the echoed
PGRMC sentence will contain the current default values. Current default values can also be obtained
by sending “$PGRMCE” to the board.
$PGRMC,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>,<13>,<14>*hh<CR><LF>
<1> Fix mode, A = automatic, 2 = 2D exclusively (host must supply altitude), 3 = 3D exclusively
<2> Altitude above/below mean sea level, -1500.0 to 18000.0 meters
<3> Earth datum index. If the user datum index (96) is specified, fields <4> through <8> must
contain valid values. Otherwise, fields <4> through <8> must be null. Refer to Appendix A for
a list of earth datums and the corresponding earth datum index.
<4> User earth datum semi-major axis, 6360000.0 to 6380000.0 meters (.001 meters resolution)
<5> User earth datum inverse flattening factor, 285.0 to 310.0 (10
-9 resolution)
<6> User earth datum delta x earth centered coordinate, -5000.0 to 5000.0 meters (1 meter res.)
<7> User earth datum delta y earth centered coordinate, -5000.0 to 5000.0 meters (1 meter res.)
<8> User earth datum delta z earth centered coordinate, -5000.0 to 5000.0 meters (1 meter res.)
<9> Differential mode, A = automatic (output DGPS data when available, non-DGPS otherwise),
D = differential exclusively (output only differential fixes)
<10> NMEA Baud rate, 1 = 1200, 2 = 2400, 3 = 4800, 4 = 9600, 5 = 19200, 6 = 300, 7 =600
<11> Velocity filter, 0=No filter, 1=Automatic filter, 2-255=Filter time constant (10 = 10 second
filter)
<12> PPS mode, 1 = No PPS, 2 = 1 Hz
<13> PPS pulse length, 0-48 = (n+1)*20msec. Example n = 4 -> 100 msec pulse
<14> Dead reckoning valid time 1-30 (sec)