Remote I/O module 16 DI
AL4103
9
Periodic signals are only detected reliably if the signal period is at least twice as long as the
cycle time.
4.4.1 Debouncing
The filter suppresses noise signals. The filter provides the input signals at the filter output with a delay
(debounce time). All signals shorter than the set debounce time are ignored by the filter.
Time diagram debounce filter:
2
1
1
1
1
0
1
0
1
0
1
t
Process data
Filter output
Filter input
1: debounce time
2: cycle time
4.4.2 Holding
The filter prolongs short input pulses. Level changes that occur during a holding period are ignored.
The filter is configured via the following parameters:
•
Hold time: pulse duration to which short pulses are to be prolonged. Pulses that are present for a
longer time than the hold time are not prolonged.
•
Hold level: signal level to be prolonged (HIGH or LOW)
Time diagram hold filter (status HIGH):
2
1
1
1
0
1
0
1
0
1
t
Process data
Filter output
Filter input
1:
hold time
2:
cycle time
Time diagram hold filter (status LOW):
2
1
1
1
0
1
0
1
0
1
t
Filter input
Filter output
Process data
1:
hold time
2:
cycle time
