FT Technologies FT742-D-SM, Руководство пользователя

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Section 7 Parameter Settings
75
FT742-SM (RS422 & RS485) Sensors
– User Manual
7.4.30 WV NMEA: Query the Wind Velocity Reading
Command
Parameter
WV (NMEA)
Command
Syntax
SET Sensor:
N/A
QUERY Sensor:
$<listenerID>,WV?*<checksum><cr><lf>
$aa,WV?*hh<cr><lf>
Sensor output:
$WIMWV,<angle>,<reference,<speed>,<units>,<status>*
<checksum><cr><lf>
$WIMWV,xxx,R,xxx.x,c,A*hh<cr><lf>
Parameters
<angle>
000 to 359
Measured wind direction in degrees relative to sensor datum
<speed>
000.0 to 075.0
Measured wind speed (in metres per second).
000.0 to 145.8
Measured wind speed (in knots).
000.0 to 270.0
Measured wind speed (in km per hour).
<reference>
R Relative (compass disabled)
T True (compass enabled)
<units>
M
Indicates the wind speed is presented in metres/second
N
Indicates the wind speed is presented in knots
K
Indicates the wind speed is presented in kilometres/hour
< status >
0 to Z
Indicates whether an error condition was detected by the operating
system, such as out of range wind speed or incorrect signal level.
Any character other than ‘A’ (ASCII 41(HEX)) = error.
Examples
Example 1
The following example illustrates the NMEA wind velocity data format. The example
shows the sensor output in m/s with a wind speed of 20m/s and a wind angle of 45°.
Message Comment
$01,WV?*13<cr><lf>
Query the wind velocity
$WIMWV,045,R,020.0,M,A*3D<cr><lf>
Sensor NMEA response
Example 2
The following example illustrates the NMEA wind velocity data format. The example
shows the sensor output in knots with a wind speed of 30.6 knots and a wind angle of 9°.
Message Comment
$01,WV?*13<cr><lf>
Query the wind velocity
$WIMWV,009,R,030.6,N,A*31<cr><lf>
Sensor NMEA response
Description
The WV command returns the wind velocity value in the currently selected format and
units. Polar or NMEA formats are available. Use the DF command, Section 7.4.8, to
select
the required output format and units.
Polar Format: The sensor returns the magnitude of the wind speed (m/s) and the wind
direction (0-359°) (see WV Polar, Section 7.4.29).
NMEA 0183 Format: The sensor returns the NMEA 0183 Wind Speed and Angle
sentence MWV. The sensor returns the wind direction (0-359°) and wind speed (m/s,
knots or km/h) using the MWV Wind Speed and Angle sentence. The sensor Talker ID
can be modified by the ID command (be aware that changing the Talker ID may result in
incompatible NMEA 0183 data formatting)
End of Manual
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