The Alarm Configuration tab has five sections: Disable Alarm for a Period of Time, Uptime Options, Process Filter Tag Override, Deadband Settings, and Alarm Categorization.
Alarms can be temporarily disabled for a period of time, for example during planned maintenance.
Disable: Check to temporarily disable the alarm.
From: The start time of the disable period.
Until: The end time of the disable period.
The uptime options control how the alarm handles bad quality data and the process filter.
Ignore Bad Data Quality: Bad quality points will not set off the alarm.
Ignore Filter Tag (uptime tag): The alarm can enter the ON state when the filter tag is on (generally means the process is down). If this setting is not checked, the alarm will not turn on when the process is down even if the alarm condition is true.
Close Filter On: If a tag is in alarm, the alarm will be ended when the filter tag turns on (generally meaning the process is down) meaning that an active alarm will be turned off if the process the tag belongs to goes down. If the checkbox is not checked then a tag that is in alarm will continue to be in alarm if the process goes down.
The Alarm can use a filter tag other than the process area’s filter tag.
Tag: The alternate filter tag.
Filter Above Value: The alarm will use this filter when the value of the tag is above this value.
Filter Below Value: The alarm will use this filter when the value of the tag is below this value.
The deadband settings are used to filter out extraneous alarms.
Deadband Alarm ON by Time: After alarm conditions are met, how long to wait before recording the start of an alarm event. If the alarm conditions persist for less than the deadband interval, no event is recorded. Use this to prevent lots of very short alarm events. Despite the deadband, the time when alarm conditions were met is the start time of the alarm.
Wait for Next Point: If no new datapoint is detected during the deadband, how long to wait for a new datapoint after the deadband time expires before re-evaluating whether alarm conditions persist. If the new datapoint does not fulfill the alarm conditions, no alarm is recorded. If this interval expires and no new datapoint is retrieved, the previous datapoint is used. Use this to account for the scenario where no new data comes in during the deadband interval, rendering it ineffective. This prevents misleading alarms, like when data connections are lost, rather than actual conditions-based alarms.
Deadband Alarm OFF by Time: After alarm conditions are cleared, how long to wait before recording the end of an alarm event. If the alarm conditions re-occur during the deadband interval, no end time is recorded. Use this to prevent having two events with a very narrow gap between them, when they would most likely be considered the same event. Despite the deadband, the time when alarm conditions were cleared is the end time of the alarm.
Wait for Next Point: If no new datapoint is detected during the deadband, how long to wait for a new datapoint after deadband time expires before re-evaluating whether alarm conditions persist. If the new datapoint does not continue the alarm, the alarm ends. If this interval expires and no new datapoint is retrieved, the previous datapoint is used. Again, treat this like an additional deadband interval to account for the possibility of not basing alarm event evaluation on actual data.
Deadband Alarm ON by Product: Data points must exceed the limit consecutively for a specified number new product tag values in a row for an alarm event to start.
The Alarm Categorization cover how alarms are sorted for reporting and some default acknowledgment values.
Alarm Priority: The Priority of the Alarm can be set by choosing from Low, Medium, or High. The priority affects the color of the alarm in Alarm Lists.
Alarm Categories: The Category of the Alarm can be chosen from Electrical, Instrumental, Mechanical, Process, or Environmental. Additional categories can be configured in System Configuration. This is used for filtering in the Alarm List and Pareto displays.
Alarm Evidence: Select an evidence class for the alarm. If both the alarm itself and a selected reason have evidence configured, both evidence classes will be applied to the alarm event, unless this would result in a duplicate.
Override Process Top Cause: Check to override the top cause configured for the alarm’s process area.
Alarm Cause: When assigning reasons for this alarm, this will be the starting branch of the reason tree. Only reasons below the top cause can be selected.
Top Cause: Open the reason selector to pick a top cause.
Clear Reason: Clear the selected reason.
Default Comment: Default text entry for the comment field.