
FASTRAK MANUAL
Rev. G
82
JUNE 2012
Example:
To select medium filtering, type x4<>
The filter is a single-pole low-pass type with an adaptive pole location (i.e., a
floating filter “parameter/variable”). The pole location is constrained within the
boundary values
FLOW
and
FHIGH
but is continuously self-adaptive between
these limits as a function of the sensitivity parameter
F
and the sensed (ambient
noise plus translational rate) input conditions. For input “rate” conditions that fall
within the adaptive range, the adaptive feature varies the pole location between
the
FLOW
and
FHIGH
limits so as to minimize the output resolution for static
inputs while minimizing the output lag for dynamic inputs. Whenever the input
conditions cause the filter to make a transition to a narrower bandwidth (i.e.,
increased filtering), the transition rate of the pole location is constrained to a
maximum allowable rate by the parameter
FACTOR
. If all of the optional
parameters are omitted, the current value of each parameter is returned to the
caller as an output record of type ‘x’.
Relatives:
None.
Default:
The default mode for all filter parameters is “medium.” These settings may be
used as a starting point for determining optimum filtering in your particular
environment.
F
0.2
FLOW
0.2
FHIGH
0.8
FACTOR
0.95
Example:
Although they are already stored in the system EEPROM, medium filtering can
be selected by sending the following command to the system:
x.2,.2,.8,.95<>
All active stations will now have medium filtering applied to the position
measurements.
RECORD IDENTIFIER ........ x
INITIATING COMMAND ....... x
byte(s)
Identification
Format
1 ...
Record type, “2”
A1
2 ...
Blank
A1
3 ...
Sub-record type ‘x’
A1
4-10 ...
Filter sensitivity
bSx.xxx
11-17 ...
Floating filter low value
bSx.xxx
18-24 ...
Floating filter high value
bSx.xxx
25-31 ...
Transition rate maximum
bSx.xxx
32-33 ...
Carriage return, line feed