Jump Response - Siemens Metro 21 M216KA Operator's Manual

Time Response of
the Digital
First-Order
Low-Pass Filter
Calculation of the
Time Response

Jump Response

ET 200L, ET 200L-SC and ET 200L-SC IM-SC Distributed I/O Device
EWA 4NEB 780 6009-02c
SC Analog Electronic Modules – T echnical Data
The smoothing is adjustable in 4 steps. Smoothing factor k multiplied by the
cycle time of the electronic module corresponds to the time constant of the
smoothing filter.
Smoothing factor: k:
None 1
Weak 8
Medium 64
Strong 128
You can calculate the time response for any jump of the input value x and the
smoothing factor k by using the following formula:
x n (k – 1) y n–1
y n :
k
y = value passed to system in current cycle n
n
Figure 12-9 shows the jump response for various smoothing factors, depend-
ing on the number of module cycles.
1
0.63
0.5
0
k = 8
k = 64
k = 128
Figure 12-15 Jump Response
100 200
Module cycles
300 400
12-29