Siemens siprotec 7SA6, Manual

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Configuration
5-37
7SA6 Manual
C53000-G1176-C156-2
5.2.6 Settings for Contact Chatter Blocking
Contact Chatter
Suppression The contact chatter filter checks whether the number of condition changes at a binary
input exceeds a preset value during a predetermined time interval. If this occurs, the
binary input will be blocked for a certain time, so the event list does not contain a large
number of unnecessary entries. The setting values necessary for this feature may be
entered in a dialogue box, as shown in Figure 5-33. This dialogue box can be found
from the open configuration matrix by clicking
Options
in the menu bar and then se-
lecting
Chatter Blocking
.
Figure 5-33 DIGSI
®
4: Setting the chatter blocking feature
Defining the Moni-
toring Criteria The operating mode of the chatter blocking feature is determined by five settings:
•
Number of permissible state changes
This setting establishes how often the state of a binary input within the
Initial
Test Time
may change. If this number is exceeded, the binary input is or remains
blocked. If the setting is 0 the chatter blocking is disabled.
•
Initial test time
Within this time interval (in seconds), the number of state changes of a binary input
is checked. The time interval begins with the first activation of a signal to the binary
input.
• Number of chatter tests
This number represents how many check cycles should be conducted before the
binary input is finally blocked. Please consider that even a high set value can be
reached over the normal life span of the device and could lead to blocking of the
binary input. Therefore this value can also be set to infinity. For this, enter the char-
acter sequence of oo.
• Chatter Idle Time
If the
Number of permissible state changes
at a binary input is exceeded
during the
Initial test time
or the
Subsequent test time
, the
Chatter
idle time
interval is initiated. The affected binary input is blocked for this time
interval. The
Chatter idle time
setting is entered in minutes. This settings can
only be programmed if the
Number of chatter tests
is not set to zero.
•
Subsequent test time
– Within this time interval, the number of state changes
at a binary input is checked again. This interval begins after the
Chatter idle
time
interval has expired. If the number of state changes is within allowable limits,
the binary input is released. Otherwise, the idle interval is restarted, until the maxi-
mum
Number chatter tests
is reached again. The
Subsequent test time
setting is entered in seconds. This settings can only be programmed if the
Number
of chatter
tests is not set to zero.