Siemens 7SJ82 Manual page 163

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Subsequent test time
During this second test time, the number of times a signal changes its status is checked once again. The
time begins when the Chatter idle time expires. If the number of status changes is within the
permissible limits, the signal is released. Otherwise, an additional dead time begins, unless the maximum
number of chatter tests has been reached.
Enter a number between 2 and 65535 in this field. The number entered corresponds to the time in
seconds. An entry here is only considered if the number of chatter tests does not equal 0.
Example 1: Permanent Blocking
The chatter-blocking settings are set as follows:
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No. permis.state changes = 4
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No. of chatter tests = 2
After more than 4 state changes within the Initial test time, the input signal is set to the original state
by the chatter blocking and the oscillatory quality is assigned. Additionally, a corresponding indication is
added to the operational log. At the same time, the
settable Chatter idle time, during the following Subsequent test time, it is checked whether the
input signal is still chattering. This check is repeated, as the No. of chatter tests is set to 2 in this
example.
If, during the 2nd Subsequent test time, it has been detected that the number of status changes of the
input signal exceeds the set No. permis.state changes, the chatter blocking detects a persistent viola-
tion of the signal stability and sets the
nently frozen. Only a device restart removes the chatter blocking again.
[dw_chatter-block-01, 1, en_US]
Figure 3-81
(1) The input signal is permanently blocked starting from this point in time.
SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
Group warning indication. The original state of the signal is perma-
Signal Change during Chatter Blocking with too Important Number of Signal State Changes
During 2nd Subsequent Test Time
Chatter blocking indication is set. After expiry of the
System Functions
3.8 Other Functions
163