Impulse Counter Inputs - ABB REG316 4 Series Operating Instructions Manual

REG 316*4 1MRB520049-Uen / Rev. F
· Where only the measurement part of the function is in use,
the binary impulse and reset inputs of both impulse counters
must be disabled, i.e. "always FALSE".
3.7.5.1.

Impulse counter inputs

The impulses counted are normally generated by a measuring or
metering device (see Fig. 3.7.5.1).
t
Fig. 3.7.5.1 Impulse counter input signal
The maximum impulse repetition rate is 25 Hz (see Fig. 3.7.5.1).
Thus the minimum time between the positive-going edges of two
input impulses is
The pulse-width is determined by the function generating the
impulses and the ratio between the pulse-width and the interval
between lagging and leading edges should be in the range 1:3 to
1:1, i.e.:
t
Pulse ,
Since the impulse counter is polled approximately every 5 ms,
impulses are reliably detected with a safety factor of about 2.
The impulse counter evaluates the positive-going edges (0 à 1)
of the input signal.
To filter any contact bounce (debouncing) phenomena, only the
first positive-going edge is evaluated within a given period
(typically 10 ms).
1
=
T
Pulse
f
Pulse
t
Pulse Pause
T
Puls , min
1
= ´
T
min Pulse , min
+
1 3
1
= = .
Hz 40 ms
25
1
= ´ =
T 10
Pulse , min
4
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.
ms
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