Section 6
Parameter Settings
34
FT742-SM (RS422 & RS485) Sensors
– User Manual
7.4.2
CF: Set or Query the Wind Compass Settings
Command
Parameter
CF(heading)
Command
Syntax
SET Sensor:
$<listenerID>,CF<mode>*<checksum><cr><lf>
$aa,CFc*hh<cr><lf>
$<listenerID>,CF<heading>*<checksum><cr><lf>
$aa,CFxxx.x*hh<cr><lf>
QUERY Sensor:
$<listenerID>,CF?*<checksum><cr><lf>
$aa,CF?*hh<cr><lf>
FT742-SM output:
$<talkerID>,CF=<mode>,<status>,<heading>,<dec>*
<checksum><cr><lf>
$aa,CF=c,c,xxx.x,xxx.x*hh<cr><lf>
Parameters
<heading>
000.0 to 359.9
Compass heading in degrees
<mode>
C
D
E
MS
Enable calibration mode
Disable compass function
Enable compass function
Save compass calibration
<status>
D
V
Compass module either disabled or not present
Valid compass reading
<dec>
000.0 to 359.9
Declination angle. Standard convention requires that westward declination
angles are subtracted from magnetic heading in order to derive true
heading. Conversely eastward declination angles are added to magnetic
heading. However, since the declination angle on the FT742-SM is
provided in the form 0 to 359.9°, the user must write westerly declination
in the form (360
– westerly declination). For example, a westerly
declination of 10° would be sent to the FT742-SM as 350°.
Examples
Example 1
Set the declination angle to 5° East and read the compass heading and declination parameters:
Message
Comment
$01,CF005.0*//<cr><lf>
Set declination angle to 5°
$01,CF?*//<cr><lf>
Query compass parameters
$WI,CF=D,D,005.0,005.0*26<cr><lf>
FT742-SM output
Example 2
The datum direction of the FT742-SM is pointing 40° to the East
– set the declination angle a
further 5° East and read the compass heading and declination parameters:
Message
Comment
$01,CF005.0*//<cr><lf>
Set declination angle to 5°
$01,CF?*//<cr><lf>
Query parameters
$WI,CF=E,V,045.0,005.0*31<cr><lf>
FT742-SM output
Example 3
Enable, query and disable the compass:
Message
$01,CFE*//<cr><lf>
$01,CF?*//<cr><lf>
$WI,CF=E,V,000.0,000.0*35<cr><lf>
$01,CFD*//<cr><lf>
Enable compass
Query compass setting
FT742-SM output (enabled)
Disable compass
