Siemens Simatic S7-300 Technical Data Manual page 147

In the two graphics below we illustrate how the 50 Hz and 60 Hz interference suppression
work
Example of a 50-Hz parasitic frequency suppression (integration time corresponds to 20 ms)
Cycle 1
Cycle 2
Figure 6-5
CPU 31xC and CPU 31x, Technical data
Manual, Edition 08/2004, A5E00105475-05
1.05 ms 1.05 ms 1.05 ms
. . .
Value Value Value
2 3
1
1 averaged measured value
1.05 ms 1.05 ms 1.05 ms
. . .
Value Value
Value
1 2 3
1 averaged measured value
50 Hz interference suppression
6.6 Technical data of the integrated I/O
1.05 ms 1.05 ms
Value Value
19 20
1.05 ms
1.05 ms
Value
Value
19 20
Technical data of CPU 31xC
6-37