Settings For Contact Chatter Blocking - Siemens siprotec 7SA6 User Manual

5.2.7

Settings for Contact Chatter Blocking

Contact Chatter
Blocking
Defining the
Monitoring Criteria
7SA6 Manual
C53000-G1176-C133-1
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 2SWLRQV in the menu bar and then
selecting &KDWWHU %ORFNLQJ.
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Figure 5-33 DIGSI 4: Setting the chatter blocking feature
The operating mode of the chatter blocking feature is determined by five settings:
• 1XPEHU RI SHUPLVVLEOH VWDWH FKDQJHV
This setting establishes how often the state of a binary input within the ,QLWLDO
7HVW 7LPH may change. If this number is exceeded, the binary input is or remains
blocked. If the setting is 0 the chatter blocking is disabled.
• ,QLWLDO WHVW WLPH
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.
• 1XPEHU RI FKDWWHU WHVWV
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
character sequence of oo .
• &KDWWHU ,GOH 7LPH
If the 1XPEHU RI SHUPLVVLEOH VWDWH FKDQJHV at a binary input is exceeded
during the ,QLWLDO WHVW WLPH or the 6XEVHTXHQW WHVW WLPH, the &KDWWHU
LGOH WLPH interval is initiated. The affected binary input is blocked for this time
interval. The &KDWWHU LGOH WLPH setting is entered in minutes. This settings can
only be programmed if the 1XPEHU RI FKDWWHU WHVWV is not set to zero.
• 6XEVHTXHQW WHVW WLPH – Within this time interval, the number of state changes
at a binary input is checked again. This interval begins after the &KDWWHU LGOH
WLPH 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
maximum 1XPEHU FKDWWHU WHVWV is reached again. The 6XEVHTXHQW WHVW
WLPH setting is entered in seconds. This settings can only be programmed if the
1XPEHU RI FKDWWHU tests is not set to zero.
Configuration
5-35