PMA KS 98 - Time Functions; LEAD (Differentiator)

14 Time functions
14.1 LEAD ( differentiator )
The differentiator forms the difference quotient according to equation:
() () () ()
{}
[]
yt
T
TT
yt t a xt xt t y
s
ss11 110
=
+
×-+× -- +
ts sampling interval x1(t) instantaneous x1
T
time constant x1(t-ts) previous x1
a
gain y1(t) instantaneous y1
y0 output offset y1(t-ts) previous y1
C
T
TTs
=
+
<1
( differentiation constant )
The complex transfer function reads:
F
aTp
Tp
p()
=
××
×+1
Inputs/outputs:
Digital input
reset
= 1 causes that y1= y0 and the difference quotient is set to 0.
= 0 starts differentiation automatically.
Analog input
x1
Input variable to be differentiated
Output
y1
Differentiator output
Parameters:
Parameters Description
Range
Default
a
Gain factor -29 999...999 999 1
y0
Output offset -29 999...999 999 0
T
Time constant in s 0...199999 1
Configuration:
Configuration Description Value Default
Mode
Differentiator
operation
Differentiating all changes
0
0
Differentiating only positive changes dx/dt >0,
1
Differentiating only negative changes dx/dt <0
2
9499 040 50611 Time functions
75 LEAD ( differentiator )