Monitoring System Health with Alarms

Set rules that trigger alarm instances when a tag value meets certain conditions.

1. In Tag Viewer, double-click the tag for which you want to create an alarm rule.
2. Under Alarm Rules, click Create.
3. Specify a name for the rule.
4. Specify a tag path to search for.
   • To apply the alarm rule to one tag, specify the absolute path of the tag.
   • To apply the alarm rule to multiple tags of the same data type, use the wildcard character (*) to represent any number of characters in the path.
   The table below illustrates examples of each type of tag search path.

   Example Tag Search Path	Result
   system1.Health.Disk.Total	Searches for one tag, system1.Health.Disk.Total.
   *.Health.Disk.Total	Searches for all tags ending with .Health.Disk.Total.

5. Specify the data type of the tag(s) for which you are creating an alarm rule. The data type you specify must match the data type specified in the tag.
6. Specify a name and description to appear each time the alarm instance becomes active.
7. Configure conditions to specify when this rule creates an alarm.
   1. Under Conditions, click Create.
   2. Choose the Severity Level you want to define conditions for.
   3. Choose the Comparator you want the alarm rule to use to process values.
   4. Specify a Set Point, or target value, for the tag this alarm rule monitors.
   5. Specify a Deadband for the alarm. The deadband determines how far the tag value must be from the set point to clear an active alarm. Use the following table to determine how deadband values operate in each comparison scenario.

      Comparator	Value needed to clear the alarm
      Less Than	Any value greater than or equal to [Set Point]+[Deadband]
      Less Than or Equal	Any value greater than [Set Point]+[Deadband]
      Greater Than	Any value less than or equal to [Set Point]-[Deadband]
      Greater Than or Equal	Any value less than [Set Point]-[Deadband]
      In Range	Any value less than [Set Point (Low)]-[Deadband] or greater than [Set Point (High)]+[Deadband]
      Equal	Any value equal to [Set Point]+[Deadband]
      Not Equal	Any value not equal to [Set Point]+[Deadband]

   6. Choose a notification strategy to alert users about alarm activity. Users specified in the strategy receive notifications whenever the alarm reaches a new maximum severity. For example, users a receive notification if a change in tag values causes a moderate-severity alarm instance to become high severity.
   7. Click Create.
8. Click Create at the top of the page.
9. When an alarm rule triggers an alarm, you can clear the alarm, acknowledge it, or neither. The following table illustrates the alarm states that result from different actions you perform on an active alarm.

   Clear?	Acknowledged?	Resulting alarm state
   Yes, due to change in tag value	Yes	Alarm becomes inactive.
   Yes, due to change in tag value	No	Alarm stays active.
   Yes, due to user force clearing the alarm instance	Yes (force clearing acknowledges the alarm)	Alarm becomes inactive.
   No	Yes	Alarm becomes acknowledged but stays active.
   No	No	Alarm stays active.