AL4142
Remote I/O module 16 DI
10
4.4.3 Inverting
The filter inverts signals.
4.4.4 Filter combination
The filters can be combined.
Example: All 3 filters are activated
Time diagram:
0
1
0
1
0
1
0
1
0
1
t
1
Digital input
Filter Debounce
Filter Hold
Filter Inverter
Process data
Digitaleingang
Filter Entprellen
Filter Halten
Filter Invertieren
Prozessdaten
1: Cycle time
4.5 Counter
The device features one counter module per port.
A counter module consists of 2 separate counters:
•
Main counter: The main counter counts the rising edges of the filtered digital input signals. The
main counter has a value range that is defined by a threshold value. If the value range of the main
counter is exceeded or not reached, an overflow or underflow signal is sent to the batch counter.
•
Batch counter: The batch counter counts the overflow or underflow signals of the main counter.
Filter module pin 4
Filter module pin 2
Count input
Count input /
control input
Main counter
Batch counter
Process data
Process data
Counter module
A counter module can be operated in different operating modes. The following operating modes are
available.
4.5.1 Counter mode CTU
In CTU (Count Up) mode, the counter module operates as an up counter with overflow detection and
overflow counter.
Behaviour:
•
The initial value of the main counter is m = 0. The initial value of the batch counter is b = 0. The
main counter has a threshold value CT. The batch counter has a threshold value CTb.
