Festo CPX-P-8DE-N Series, Description

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3. Input module CPX-P-8DE-N-...
3-19
Festo P.BE-CPX-P-EA-EN en 1209NH English
3.3.5 Operating mode B - Counter
The counters count rising or falling edges of the digitised
input signal upwards or downwards depending on
parameterisation.
Certain parameter alterations cause an initialisation of the
respective channel. Counters are thereby reset to the starting
value (lower or upper limit value) (
section 3.3.8).
Chan-
nel Counter properties
0 … 3 Control possibilities
– Start, stop, reset via byte 0 of the PIO
– Current counter setting in byte 2 … 9 of the PII
1)
– Alarm signal in byte 0 of the PII
Parameterisable properties:
– Limit values can be freely selected within the range of
values
– Incremental or decremental counter
– Counting of falling or rising signal edges
2)
– Input debounce times are taken into consideration
2)
(signal extension time is ignored)
– Diagnostic response upon reaching the limit value can
be influenced
Maximum values:
– max. counting rate: 1250 Hz
– min. pulse length: 400 µs
– min. signal pause: 400 µs
– max. counting range: -32768 to 32767
1)
Only applicable for extended process image ( Tab. 3/10)
2)
The edges of the debounced signal are counted. The debounce
time limits the max. counting rate. At a debounce time of 3 ms, for
example, this is approx. 166 Hz.
Tab. 3/11: Counter properties (operating mode B)
The “Counter input” operating mode is specified via the para-
meter “Operating mode of the input channel” (
Tab. 3/20).
The counter is controlled (start, stop, reset) via the process
image outputs (
Tab. 3/10).