Siemens Metro 21 M216KA, Руководство оператора

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12-11
ET 200L, ET 200L-SC and ET 200L-SC IM-SC Distributed I/O Device
EWA 4NEB 780 6009-02c
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:
yn :
+
xn
)
(k – 1) yn–1
k
y
n
= value passed to the system in the current cycle n
Figure 12-3 shows the jump response for various smoothing factors, depend-
ing on the number of module cycles.
0.5
1
0
0.63
100 200 300 400
Module cycles
k = 8
k = 64
k = 128
Jump Response
Figure 12-6 Jump response
Time Response of
the Digital
First-Order
Low-Pass Filter
Calculation of the
Time Response
Jump Response
SC Analog Electronic Modules – T echnical Data