Section 6
Parameter Settings
37
FT742-SM (RS422 & RS485) Sensors
– User Manual
7.4.4
DF: Set or Query the Wind Velocity Data Format
Command
Parameter
DF
Command
Syntax
SET Sensor:
$<listenerID>,DF<format>*<checksum><cr><lf>
$aa,DFc*hh<cr><lf>
or
$aa,DFcc*hh<cr><lf>
QUERY Sensor:
$<listenerID>,DF?*<checksum><cr><lf>
$aa,DF?*hh<cr><lf>
Sensor output:
$<talkerID>,DF=<format>*<checksum><cr><lf>
$aa,DF=c*hh<cr><lf>
Parameters
<format>
P
Set the data format to Polar (wind speed and direction) (Factory
Default Setting)
N
Set the data format to NMEA 0183 with wind speed in m/s
NN
Set the data format to NMEA 0183 with wind speed in knots
NK
Set the data format to NMEA 0183 with wind speed in km/h
Examples
Example 1
Set the wind velocity output data format to NMEA with wind speed in m/s and verify the new
setting.
Message
Comment
$01,DFN*//<cr><lf>
Set format to NMEA (m/s)
$01,DF?*//<cr><lf>
Query format setting
$WI,DF=N*43<cr><lf>
Sensor response
Example 2
Set the wind velocity output data format to NMEA with
wind speed in knots and verify the new setting.
Message
Comment
$01,DFNN*//<cr><lf>
Set format to NMEA (knots)
$01,DF?*//<cr><lf>
Query format setting
$WI,DF=NN*0D<cr><lf>
Sensor response
Description
Use the DF command to set the required format of the wind velocity readings. See
command WV (Sections 7.4.26 and 7.4.27) for a description of the sensor output for each of
the format types.
When a DF Set command is sent to the sensor, a reset of the minimum and maximum
readings to their default values is automatically performed.
Polar Format: The sensor returns the magnitude of the wind speed (m/s only) and the wind
direction (0-359 degrees).
NMEA 0183 Format: The sensor returns the wind angle (0-359 degrees, Relative) and wind
speed (m/s, knots or km/h). The sensor TalkerID is always set to WI when NMEA format is
selected irrespective of any value that may have been set with the ID command.
