Delay timer interaction

There are two timers used to delay the analysis or reporting of an alarm. These timers are used to allow normal functions to occur before an object’s behavior appears abnormal and generates an alarm. The first timer is the Alarm State: Reference Delay Timer, which allows a preset amount of time to pass between commanding an object and making sure that the commanded object has obeyed the command before considering an alarm condition to be present. The second timer is the Alarm State: Report Delay Timer, which prevents the analysis of an object’s condition until the preset time has passed after that object has appeared to obey a command.

The length of the reference delay time is a combination of the reference delay time and the report delay time settings. If you change the warning reference, both delays go active; and if the reference delay time is greater than or equal to the report delay time, then the total delay is the sum of both timer settings. However, if the reference delay time is less than the report delay time, then the delay is equal to the report delay time setting.

The delay timers of the alarm extensions interact as follows:

Note: If no Warning Limits are defined, the Reference Delay Time and Reference Delay Timer Active attributes do not apply.
Figure: Delay timer interaction


Table 1. Delay timer interaction description
Number Name User action
1 Warning reference command Commands the Warning reference to change, moves the setpoint and the corresponding High and Low warnings.
2 Reference Delay Timer Timer starts when the Warning Reference changes.
3 Report Delay Interval Interval starts if high or low warning is exceeded. The delay is applied on both the entrance into the alarm condition and the exit out of the alarm condition.
4 After Report Delay Interval Input reference is analyzed for alarm conditions.