Siemens Simatic S7-400 - Manual (Page 311)

Analog Modules
5-95
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
Smoothing of the Measured Values
You will find information that is generally applicable to the smoothing of analog
values in Section 5.6. You can only set strong smoothing for the SM 431; AI 8
14
Bit.
The module cycle time is a constant, irrespective of how many channels are
enabled. It therefore has no effect on the filter settling time, which is defined by the
parameter assignment of interference frequency suppression and smoothing.
Note
It is only advisable to parameterize smoothing if you also parameterize
interference frequency suppression; otherwise, the measured value resolution will
be reduced to 9 bits (analog value representation is right aligned in this case).
Filter Settling Time with Strong Smoothing
Table 5-57 Interference Frequency Suppression and Filter Settling Time with Smoothing of
the SM 431; AI 8 14 Bit (6ES7431-1KF20-0AB0)
Interference Suppression Smoothing Filter settling time in ms
None High –
50 Hz High 100
60 Hz High 83.333
400 Hz High 12.5