Siemens SIMATIC ET 200S Manual page 302

Digital Electronic Modules
Pulse extension
Pulse extension is a function that changes a digital input signal. A pulse at a digital
input is extended to at least the parameterized length. If the input pulse already
longer than the parameterized length, the pulse is not changed.
The principle of pulse extension
The following figure uses examples to illustrate how and when input pulses are
changed.
Parameter for pulse extension = T
T for edge 0 to 1
1
Process signal
"Processed"
input signal
Pulse is shorter than T
and is lengthened to T
Process signal
"Processed"
input signal
A second pulse occurring during the
current pulse extension is postponed
until the current pulse extension is
completed.
Figure 12-1 The principle of pulse extension
12-6
1
T for edge 1 to 0
1
1
1.
Pulse is longer than T
1
is not changed.
Short pulses that occur
during the current pulse
extension are ignored.
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