The Delay feature only applies to redirection actions that are to trigger automatically, or both manually and automatically (see Define the Trigger Type).
The Delay feature allows you to suspend an alarm redirection for a defined amount of time. It allows you to stop alarms from being redirected when the selected database item’s alarm state value is fleeting between alarm states.
You can also use the Delay feature to create a cascade of alarm redirections. For example, you can redirect an alarm to an engineer, and if the alarm is not acknowledged or cleared within the delay time, the alarm can be redirected to another User account or User Group. This can be repeated so that an alarm could be redirected several times. This is referred to as a cascade.
When a selected item has an alarm that is in the Trigger State(see Define the Trigger State), the Delay timer begins. The alarm is not redirected until the Delay time period expires. (If required, you can cancel and then later restart any alarm redirections for which the Delay period has not yet expired—see CancelRedirections and RestartRedirections Methods.)
If the alarm changes from the Trigger State to the Abort State(see Define the Abort State) within the Delay time, the alarm is not redirected.
To define the Delay, after you Define the Severity Range:
- Enter the Delay amount and its time units in the Delay field. Enter the required interval in the OPC Time Format. You can enter the value directly in the field, or use the Interval window (accessed via the field's browse button) to specify the required value.
Example:
1H 30M gives a delay of 1 hour 30 minutes.
To redirect an alarm as soon as it is raised, you should set the Delay to 0, and the Abort State to ‘Never’ (see Define the Abort State).
If you want to stop alarms being redirected when a value is fleeting into and out of an alarm limit, you should set the Delay to a short amount of time, such as 30S (30 seconds). You will need to set an appropriate Abort State, so that the alarm redirection is canceled if the alarm is cleared, acknowledged, or both during the Delay.
For cascaded alarm redirections, you should allocate enough time for someone to respond to the alarm. For example, you could allocate 2H (2 hours) for an engineer to repair an inoperative instrument. You could also set the Abort State so that the alarm redirection is canceled if the engineer acknowledges the alarm.
For an example of how the Delay and Abort State can be used to create a small cascade, see Use Alarm Redirection to Send Alarm Details in an E-Mail.