Siemens SIMATIC ET 200S Manual page 425

Smoothing
The individual measured values are smoothed by means of digital filtering. The
smoothing can be adjusted in 4 steps, where the smoothing factor k multiplied by
the cycle time of the electronic module corresponds to the time constant of the
smoothing filter. The greater the smoothing, the greater the time constant of the
filter.
The figures below show the step response for the different smoothing factors
depending on the number of module cycles.
• Smoothing in the case of the 2AI U Standard, 2AI U High Feature, 2AI I 2WIRE
Standard, 2AI I 4WIRE Standard, 2AI I 2/4WIRE High Feature, 2AI RTD
Standard, 2AI RTD High Feature, 2AI TC Standard, 2AI TC High Feature
None: k=1
1
0.63
0.5
0
Figure 13-5
ET 200S Distributed I/O System
EWA-4NEB780602402-09
Weak: k=4
100
50
Smoothing in the case of the 2AI U Standard, 2AI U High Feature, 2AI I
2WIRE Standard, 2AI I 4WIRE Standard, 2AI I 2/4WIRE High Feature,
2AI RTD Standard, 2AI RTD High Feature, 2AI TC Standard, 2AI TC High
Feature
Analog Electronic Modules
Medium: k=32
150 200
Module cycles
Strong: k=64
250 300
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