Chatter Monitoring - Siemens SIMATIC ET 200SP Equipment Manual

Parameters/address space
4.2 Explanation of parameters
4.2.4.5

Chatter monitoring

Function
Chatter monitoring is a process control function for digital input signals. It detects and
reports unusual signal sequences in the process with 1oo1 evaluation, for example, an input
signal fluctuating between "0" and "1" too frequently. The occurrence of such signal
characteristics is an indication of faulty sensors or process control instability.
Recognizing unusual signal patterns
An assigned monitoring window is available for each input channel. The monitoring window
starts with the first signal change of the input signal. If the input signal changes within the
monitoring window at least as often as the assigned "Number of signal changes", a chatter
error is detected. If no chatter error is detected within the monitoring window, the next
signal change restarts the monitoring window.
If a chatter error is detected, a diagnostic is signaled. If the chatter error does not occur for
the monitoring window for three times the configured period, the diagnostic is reset.
Principle
The figure below shows the principle of chatter monitoring as a graphic.
Figure 4-1
34
Figure chatter monitoring
Digital input module F-DI 8x24VDC HF (6ES7136-6BA01-0CA0)
Equipment Manual, 10/2021, A5E50578307-AA