Proface LT4300M - 5.7 Modular HMI + Control" - Manual (Page 46)

LT Description
46
Input Management
Overview
LT is equipped with Standard Inputs and Fast Inputs. You can manage the input values using the
software filter function that eliminates the input signal noise.
This section explains the filter concept using Fast Input as an example. High-speed Counter Input
and Pulse Catch Input can be managed as Special Input and Output.
Filter Principle of Special I/O
The filter is designed to reduce the bouncing effect at the inputs. Setting a filter value allows the
controller to ignore sudden changes of input levels caused by noise.
The following timing diagram illustrates the filter effects: