Siemens SIMATIC ET 200eco PN Operating Instructions Manual page 178

I/O device analog input/analog output
10.1 I/O device analog input
Smoothing
Smoothing of the analog values produces a stable analog signal for further processing. The
smoothing of analog values is useful when handling wanted signals (measured values) with
a slow rate of change, for example, temperature measurements.
The measured values are smoothed by digital filtering. To achieve smoothing, the device
generates a mean value from a specified number of converted (digitized) analog values.
You assign a maximum of four levels for the smoothing (none, weak, medium, strong). The
level determines the number of module cycles, from which the mean value is generated.
The stronger the smoothing, the more precisely the smoothed analog value reaches the
setpoint value. The time interval until the smoothed analog value is applied after a signal
change is also prolonged.
The figure below shows the number of cycles a module requires to apply the smoothed
analog value at almost 100% after a step response, based on the smoothing function
settings. The figure applies to all signal changes at the analog input. The smoothing value
defines the number of cycles a module requires to reach 63% of the end value of the
changed signal.
①
②
③
178
Smoothing, weak
Smoothing, medium
Smoothing, strong
Operating Instructions, 08/2016, A5E01250250-AJ
ET 200eco PN