Holddown Alarms Config
Holddown alarms refer to the period of time before an alarm is raised after the actual alarm level was breached. The trigger that checks the holddown period is only fired when the last status field is changed. The trigger for holddowns is upon the status field, so even if the status hasn't changed and the period has passed, unless the last status field has been updated, no notification will be sent. The hold down period is defined as the difference between minute values on the timestamps of the data.
An example can be seen in the diagram below, where the point goes into high alert and remains in high alert after the hold down time has elapsed, so an alarm is then fired. If it had crossed into the High Alarm after the holddown period, it would display a High Alarm. And, if it had crossed below the High Alert after the hold down period, then no alarm would have been raised at all.
These can be useful to cancel out unnecessary alarms, in that no one needs to be notified if it is known that the alarm will go back to a normal status. This could be in the event of an asset going into a regular cycle or off period.
Enter the time in minutes within the relevant text fields.
Values can be copied from one point to across all points by using the Copy TO All button.
Further examples of Holddown Alarms are detailed below.
Scenario 1
- Breach of Low Alert threshold and holddown from an OK status
- Breach of Ok status threshold and holddown from a Low Alert
- Results as Expected for Low Alert
- Results differ from Expected for Ok status
- Alarm received even though holddown period had not been exceeded
Alarm Configuration
Low Alert threshold set to 0 and enabled, anything less than 0 is considered a breach.
High Alarm set to 60 and enabled, anything above 60 is considered a breach.
Low Alert holddown is set to 1, anything breaching low alert threshold for longer than a minute generates an alarm.
Ok Status holddown is set to 10, anything not breaching low alert or high alarm for longer than 10 minutes generates an alarm.
High Alarm holddown is set to 1, anything breaching high alarm threshold for longer than a minute generates an alarm.
Data Set
Expected Results
Actual Results
Alarm Table Results
Low Alert, alarm appears in list
Ok Status, alarm appears in list when it shouldn't have as holddown period should not have been breached.
Scenario 2
Alarm Configuration
Low Alert threshold set to 0 and enabled, anything less than 0 is considered a breach.
High Alert set to 30 and enabled, anything above 30 is considered a breach.
High Alarm set to 60 and enabled, anything above 60 is considered a breach.
Low Alert holddown is set to 1, anything breaching low alert threshold for longer than a minute generates an alarm.
Ok Status holddown is set to 30, anything not breaching low alert or high alarm for longer than 30 minutes generates an alarm.
High Alert holddown is set to 1, anything breaching high alert threshold for longer than a minute generates an alarm.
High Alarm holddown is set to 10, anything breaching high alarm threshold for longer than 10 minutes generates an alarm
Data Set
Expected Results
Actual Results
Alarm Table Results
High Alert, alarm appears in list
Scenario 3
Breach of High Alert and High Alarm threshold, holddown exceeded for High Alert only.
Results as Expected
Alarm Configuration
Low Alert threshold set to 0 and enabled, anything less than 0 is considered a breach.
High Alert set to 30 and enabled, anything above 30 is considered a breach.
High Alarm set to 60 and enabled, anything above 60 is considered a breach.
Ok Status holddown is set to 10, anything not breaching low alert or high alarm for longer than 10 minutes generates an alarm.
High Alert holddown is set to 10, anything breaching high alert threshold for longer than 10 minutes generates an alarm.
High Alarm holddown is set to 10, anything breaching high alarm threshold for longer than 10 minutes generates an alarm
Data Set
Expected Results
Actual Results
Alarm Table Results
High Alert, alarm appears in list.
Scenario 4
Alarm Configuration
Low Alert threshold set to 0 and enabled, anything less than 0 is considered a breach.
High Alert set to 30 and enabled, anything above 30 is considered a breach.
High Alarm set to 60 and enabled, anything above 60 is considered a breach.
Ok Status holddown is set to 10, anything not breaching low alert or high alarm for longer than 10 minutes generates an alarm.
High Alert holddown is set to 10, anything breaching high alert threshold for longer than 10 minutes generates an alarm.
High Alarm holddown is set to 10, anything breaching high alarm threshold for longer than 10 minutes generates an alarm
Data Set
Expected Results
Actual Results
Alarm Table Results
High Alert, alarm appears in list
Scenario 5
Breach of High Alert and High Alarm threshold, holddown exceeded for High Alert and High Alarm.
Results as Expected
Alarm Configuration
Low Alert threshold set to 0 and enabled, anything less than 0 is considered a breach.
High Alert set to 30 and enabled, anything above 30 is considered a breach.
High Alarm set to 60 and enabled, anything above 60 is considered a breach.
Ok Status holddown is set to 10, anything not breaching low alert or high alarm for longer than 10 minutes generates an alarm.
High Alert holddown is set to 10, anything breaching high alert threshold for longer than 10 minutes generates an alarm.
High Alarm holddown is set to 10, anything breaching high alarm threshold for longer than 10 minutes generates an alarm
Data Set
Expected Results
Actual Results
Alarm Table Results
High Alert, alarm appears in list
High Alarm, alarm appears in list
Scenario 6
Breach of High Alert and High Fault threshold, holddown exceeded for High Alert and High Alarm.
Results as Expected
Alarm Configuration
Low Alert threshold set to 0 and enabled, anything less than 0 is considered a breach.
High Alert set to 30 and enabled, anything above 30 is considered a breach.
High Fault set to 100 and enabled, anything above 60 is considered a breach.
Ok Status holddown is set to 10, anything not breaching low alert or high alarm for longer than 10 minutes generates an alarm.
High Alert holddown is set to 10, anything breaching high alert threshold for longer than 10 minutes generates an alarm.
High Fault holddown is set to 10, anything breaching high fault threshold for longer than 10 minutes generates an alarm.
Data Set
Expected Results
Actual Results
Alarm Table Results
High Alert, alarm appears in list
High Fault, alarm appears in list