Airmar NMEA 2000® Depth, Датчики - Manual (Page 33)

DST200 User Manual revision 1.000
Proprietary and Confidential
31
Speed Filter Type 1 (Basic IIR Filter)
For Speed Filter Type 1, the fields in PGN 126720-43 starting with field 5 are described below.
Field
#
Name
Request
Param. DD
DF Type Resolution Value Remark
5 Filter type Yes N/A DF52 4 bits 1 1 = basic IIR filter See remark for field 5 on page 28.
6 Reserved No DD001 DF52 4 bits 1 0xF All bits set to logic “1”
7 Sample interval No N/A DF66 uint16 0.01 s 0 to 655.32 seconds
0 = reserved
0xFFFE = restore default
0xFFFF = data not available
/ do not change
Interval of time between successive samples
of the paddlewheel pulse accumulator.
This field is stored in EEPROM and may be
changed with the Command Group Function
PGN 126208. The default value for filter type
1 is 0.25 seconds.
8 Filter duration No N/A DF66 uint16 0.01 s 0 to 655.32 seconds
0 = reserved
0xFFFE = restore default
0xFFFF = data not available
/ do not change
Duration of filter. This value must be the
sample interval value in field 7.
This field is stored in EEPROM and may be
changed with the Command Group Function
PGN 126208. The default value is 2.0
seconds.
The filter equation is:
interval Sample
duration Filter
K
K
reading New K value filtered Old
value filtered New
_
_
constant e filter tim the where
_ ) 1 ( _ _
_ _
=
+ − ×
=
and K 1. Note that if K=1, this is equivalent to no filtering at all.