The Alarm Delay property allows you to configure digital, analog, and advanced alarms so that they will not be activated unless their triggering conditions remain true for a specified period.
For analog alarms, this means the analog variable needs to fall within a specified range for the duration of the alarm delay period before an alarm will activate. In the case of digital and advanced alarms, the triggering condition of the digital variable or Cicode expression need to remain true for the delay period.
Example
An alarm delay could be useful is in monitoring temperature. By setting a delay period, you can filter out momentary alarms caused by a temperature moving in and out of different ranges.
For alarms with multiple variables configured, if you use the Alarm Delay property the delay period will start when the most recent I/O update has occurred. This delay can run concurrently with the internal multi-variable delay (MVD) which starts at the first IO update. The alarm will not be added to the queue until the period of the longest delay setting has elapsed. The alarm will then be triggered at the following 1/2 alarm scan time.
See Also
Published June 2018