Section 6 Parameter Settings
70 FT722 & FT742 (RS485) – FF & PM Sensors – User Manual
6.4.13 FL.2: Set or Query Filter Lengths
$<listenerID>,FLL<speedLen>,<dirLen>*<checksum><cr>
<lf>
$aa,FLLxxxx,xxxx*hh<cr><lf>
$<listenerID>,FL?L*<checksum><cr><lf>
$<talkerID>,FL=<speedLen>,<dirLen>*<checksum><cr><l
f>
$aa,FL=xxxx,xxxx*hh<cr><lf>
Sample size of the wind speed filter.
Number of previous readings
#
used to calculate the latest wind speed
reading, 0001 is equivalent to disabling the filter
(Factory Default Setting = 0016)
Sample size of the wind direction filter.
Number of previous readings
#
used to calculate the latest wind
direction reading, 0001 is equivalent to disabling the filter;
(Factory Default Setting = 0016)
Example 3
Modify the filter’s dimensions. Verify that the command has been accepted.
$01,FLL0001,0032*//<cr><lf>
Set speed filter length to 1 and
direction filter length to 32.
Query filter’s length settings.
$WI,FL=0001,0032*29<cr><lf>
Use this command to modify the speed and direction filter lengths. When the filter is enabled,
speed and direction readings are independently averaged by calculating the mean of the
previous number of readings
#
set by the filter lengths <speedLen> and <dirLen>.
Please note the previous readings filter length by definition includes the most up to date wind
reading at position 1. So setting a filter to a length of 0001 gives just the current reading (see
Section 2.3).
The sensor’s internal memory is large enough to retain 64 previous speed and direction
readings, allowing for maximum filter length of 6.4 seconds.