West Control Solutions KS98-1 - Manual (Page 131)

III-6.6 FILT ( filter with tolerance band (No. 55) )
The complex transfer function of the filter within a tolerance band around the last output value ( | | ) x y 1 1
- <<= d is:
F p
p T
( ) =
+ ×
1
1
With a difference higher than Diff or reset = 1 between input x1 and output y2, the filter stage is switched off
and the output follows the input directly.
With a difference of input x1 and output y1 smaller than Diff and reset = 0, the output follows an e-function
with time constant T. The output variable is calculated according to the following equation:
y t
T
T ts
y t ts
ts
T ts
x t 1 1 1 ( ) ( ) ( )
=
+
Ч - +
+
Ч ts sampling interval x(t)
T time constant x1(t-ts)
Inputs/outputs
Digital input
reset
= 0 | | x y 1 1
- < Diff
delay effective
= 0 | | x y 1 1
- >Diff
delay switched off
reset
= 1 | | x y 1 1
- <<= Diff
delay switched off
= 1 | | x y 1 1
- >Diff delay switched off
Analog input
x1
Input variable to be delayed
Analog output
y1
Delayed output variable
Parameters:
Parameter Description Range Default
T Time constant in s 0...199999 1
Diff Tolerance band } 0...999999 1
Time functions 9499-040-82711
III-131 FILT ( filter with tolerance band (No. 55) )
T
x1 y1
?1
Diff
reset
X/Y
T t
X
Y
2*Diff
Fig. 7