In the bullet list below, parent alarm refers to an alarm that meets the Parent Alarm Condition criteria and is raised on the item that is configured as a Parent Alarm Object. Child alarm refers to an alarm that is raised on a database item on which the above Parent Alarm Object is specified. For more information, see Configure any Alarm Suppression Requirements.

When 'By Alarm State' alarm suppression is configured:

• If the parent alarm goes active:
  • Geo SCADA Expert suppresses any new child alarms (see The Effects of Suppression on Alarm Displays).
  • The setting of the Suppress Pre-Existing Alarms check box on each child item determines whether any pre-existing ‘child’ alarms remain active or are also suppressed (see Configure any Alarm Suppression Requirements).
  • An event is logged for each suppressed alarm. The event record indicates whether each alarm is suppressed due to Maintenance, or Consequential, alarm suppression.
  • Alarm redirections do not trigger for any alarms that are suppressed (see Alarm Redirection and Suppressed Alarms).
  • With each child item's Status display:
    • Status attributes that relate to the state of the child item's alarms indicate whether that item's alarms are suppressed. With points, these typically comprise the State Alarm status attribute, and (if the point is an analog or counter-type point on which the No Change feature is enabled), the No Change Alarm status attribute. Other 'state alarm' status attributes might be supported and displayed for some types of database item.
      (Whether those entries indicate suppression varies depending whether the child item only has alarms that existed when the suppression came into force, and if so, whether the suppression also applies to those alarms (see Configure any Alarm Suppression Requirements).)
    • The Suppression Status attribute indicates that suppression is currently in force on that database item. (This is regardless of whether any alarms actually exist on the child item. The child item is still suppressed while the parent alarm is active, even when there are no active child alarms to suppress.)
    • The Suppressing Parent status attribute indicates the full name of the Parent Alarm Object. This is the database item that is causing this child item's alarms to be suppressed.
  • The parent alarm’s Suppressed Alarm Count (displayed, for example, on Alarms Lists and the Alarm Banner) indicates how many child alarms are suppressed
  • The parent item’s Suppressed Alarm Objects pick action provides access to a list of the child database item(s) for which alarms might be suppressed due to the parent alarm being active.
  • Suppressed child alarms can still appear on non-alarm displays, such as Mimics and Objects Lists (alarm suppression only hides the alarms on alarm displays). If the Consequential Alarms Palette is enabled, such entries use the Alarm Suppressed system color instead of the relevant Alarm Severity color, to indicate that the alarm is suppressed. (Exceptions might apply that result in non-alarm displays using neither of the above color sets. For example, if the entries on Mimics are configured to use a custom foreground color, or if Queries Lists have been customized so that the entries' foreground colors do not change in response to the items' status.)
• Once the parent alarm ceases to become active and the 'Unsuppress Delay' comes into force:

  If a child item's Unsuppress Delay is set to 0, this stage is omitted and the child alarms go straight from being suppressed to unsuppressed. If this applies, the activities mentioned in 'Once the 'Unsuppress Delay' expires' apply instead (see below).

  • The child alarms continue to remain suppressed (omitted from alarm displays).
  • Any new child alarms that are generated while the 'Unsuppress Delay' is in force are also suppressed.
  • With each child item's Status display:
    • Status attributes that relate to the state of the child item's alarms, such as the State Alarm status attribute, continue to indicate whether that child item's alarms are suppressed.
      (Whether those entries indicate suppression varies depending whether the child item only has alarms that existed when the suppression came into force, and if so, whether the suppression also applies to those alarms.)
    • The Suppression Status attribute updates to indicate that the suppression is now in a 'Clear Pending' state. (This status indicates that the parent alarm that caused the suppression is no longer active, but a delay is currently in force in case the issue that caused the parent alarm is causing fleeting changes in that parent item's point state. The delay is designed to help prevent fleeting changes in the suppression status of the child item(s).)
    • The Suppressing Parent status attribute continues to indicate the full name of the Parent Alarm Object. This is the database item that caused this child item's alarms to be suppressed.
  • Suppressed child alarms can still appear on non-alarm displays, such as Mimics and Objects Lists (alarm suppression only hides the alarms on alarm displays). If the Consequential Alarms Palette is enabled, such entries use the Alarm Suppression Clear Pending system color instead of the relevant Alarm Severity color, to indicate that the alarm is suppressed. (Exceptions might apply that result in non-alarm displays using neither of the above color sets. For example, if the entries on Mimics are configured to use a custom foreground color, or if Queries Lists have been customized so that the entries' foreground colors do not change in response to the items' status.)
• Once the 'Unsuppress Delay' expires:
  (and providing that the parent alarm remains inactive)
  • Geo SCADA Expert automatically activates any existing suppressed child alarms (see The Effects of Suppression on Alarm Displays). The newly activated alarm entries are time stamped with their occurrence time (or, on systems on which the Use Visible Time As Alarm Active Time feature is enabled, their unsuppressed time).
  • An event is logged for each existing child alarm that is unsuppressed, indicating the time that the alarm became unsuppressed
  • Any Alarm Redirection activity that applies to the child alarms comes into effect (for instance, Geo SCADA Expert starts any redirection timers).
  • With each child item's Status display:
    • Status attributes that relate to the state of the child item's alarms, such as the State Alarm status attribute, are no longer appended with a '(Suppressed)' entry.
      
    • The Suppression Status attribute indicates that the alarms are now unsuppressed.
    • The Suppressing Parent status attribute is omitted from the Status display.
  • Any child alarm entries on non-alarm displays, such as Mimics, use the relevant Alarm Severity color (unless they are configured to use a custom color).

In the bullet list below, Parent Alarm Tag refers to a property on the Parent Alarm Object that, along with an Operator and Value, is evaluated to determine if it fulfills the expression criteria that triggers 'By Expression' alarm suppression on a 'child' database item. Child alarm refers to an alarm that is raised on the database item on which the above Parent Alarm Object is specified. For more information, see Configure any Alarm Suppression Requirements.

When 'By Expression' alarm suppression is configured:

• When the value of the 'Parent Alarm Tag' fulfills the expression criteria and triggers alarm suppression:
  • Geo SCADA Expert suppresses any new child alarms (see The Effects of Suppression on Alarm Displays).
  • The setting of the Suppress Pre-Existing Alarms check box on each child item determines whether any pre-existing ‘child’ alarms remain active or are also suppressed (see Configure any Alarm Suppression Requirements).
  • An event is logged for each suppressed alarm. The event record indicates whether each alarm is suppressed due to Maintenance, or Consequential, alarm suppression.
  • Alarm redirections do not trigger for any alarms that are suppressed (see Alarm Redirection and Suppressed Alarms).
  • With each child item's Status display:
    • Status attributes that relate to the state of the child item's alarms indicate whether that item's alarms are suppressed. With points, these typically comprise the State Alarm status attribute, and (if the point is an analog or counter-type point on which the No Change feature is enabled), the No Change Alarm status attribute. Other 'state alarm' status attributes might be supported and displayed for some types of database item. (Whether those entries indicate suppression varies depending whether the child item only has alarms that existed when the suppression came into force, and if so, whether the suppression also applies to those alarms (see Configure any Alarm Suppression Requirements). For an example that demonstrates this, see Example of 'By Expression' Suppression.)
    • The Suppression Status attribute indicates that suppression is currently in force on that database item. (This is regardless of whether any alarms actually exist on the child item. The child item is still suppressed while the value of the 'Parent Alarm Tag' fulfills the expression criteria and triggers alarm suppression, even when there are no active child alarms to suppress.)
    • The Suppressing Parent status attribute indicates the full name of the Parent Alarm Object. This is the database item that is causing this child item's alarms to be suppressed.
  • The parent item’s Suppressed Alarm Objects pick action provides access to a list of the child database item(s) for which alarms might be suppressed due to the expression criteria being fulfilled.
  • Suppressed child alarms can still appear on non-alarm displays, such as Mimics and Objects Lists (alarm suppression only hides the alarms on alarm displays). If the Consequential Alarms Palette is enabled, such entries use the Alarm Suppressed system color instead of the relevant Alarm Severity color, to indicate that the alarm is suppressed. (Exceptions might apply that result in non-alarm displays using neither of the above color sets. For example, if the entries on Mimics are configured to use a custom foreground color, or if Queries Lists have been customized so that the entries' foreground colors do not change in response to the items' status.)
• Once the value of the 'Parent Alarm Tag' ceases to fulfill the expression criteria and the 'Unsuppress Delay' comes into force:

  If a child item's Unsuppress Delay is set to 0, this stage is omitted and the child alarms go straight from being suppressed to unsuppressed. If this applies, the activities mentioned in 'Once the 'Unsuppress Delay' expires' apply instead (see below).

  • The child alarms continue to remain suppressed (omitted from alarm displays).
  • Any new child alarms that are generated while the 'Unsuppress Delay' is in force are also suppressed.
  • With each child item's Status display:
    • Status attributes that relate to the state of the child item's alarms, such as the State Alarm status attribute, continue to indicate whether that child item's alarms are suppressed.
      (Whether those entries indicate suppression varies depending whether the child item only has alarms that existed when the suppression came into force, and if so, whether the suppression also applies to those alarms.)
    • The Suppression Status attribute updates to indicate that the suppression is now in a 'Clear Pending' state. (This status indicates that the value of the 'Parent Alarm Tag' that caused the suppression has changed to one that is no longer fulfilling the expression criteria. A delay is currently in force in case the change in the Parent Alarm Tag's value is only fleeting. The delay is designed to help prevent fleeting changes in the suppression status of the child item(s).)
    • The Suppressing Parent status attribute continues to indicate the full name of the Parent Alarm Object. This is the database item that caused this child item's alarms to be suppressed.
  • Suppressed child alarms can still appear on non-alarm displays, such as Mimics and Objects Lists (alarm suppression only hides the alarms on alarm displays). If the Consequential Alarms Palette is enabled, such entries use the Alarm Suppression Clear Pending system color instead of the relevant Alarm Severity color, to indicate that the alarm is suppressed. (Exceptions might apply that result in non-alarm displays using neither of the above color sets. For example, if the entries on Mimics are configured to use a custom foreground color, or if Queries Lists have been customized so that the entries' foreground colors do not change in response to the items' status.)
• Once the 'Unsuppress Delay' expires:
  (and providing that the value of the 'Parent Alarm Tag' continues to no longer fulfill the expression criteria)
  • Geo SCADA Expert automatically activates any existing suppressed child alarms (see The Effects of Suppression on Alarm Displays). The newly activated alarm entries are time stamped with their occurrence time (or, on systems on which the Use Visible Time As Alarm Active Time feature is enabled, their unsuppressed time).
  • An event is logged for each existing child alarm that is unsuppressed, indicating the time that the alarm became unsuppressed.
  • Any Alarm Redirection activity that applies to the child alarms comes into effect (for instance, Geo SCADA Expert starts any redirection timers).
  • With each child item's Status display:
    • Status attributes that relate to the state of the child item's alarms, such as the State Alarm status attribute, are no longer appended with a '(Suppressed)' entry.
      
    • The Suppression Status attribute indicates that the alarms are now unsuppressed.
    • The Suppressing Parent status attribute is omitted from the Status display.
  • Any child alarm entries on non-alarm displays, such as Mimics, use the relevant Alarm Severity color (unless they are configured to use a custom color).