The state of alarms is affected by the state of the process, equipment, system or plant. For example, when a tank is taken out of service, the level alarms associated with the tank would be no longer used, until the tank is returned to service. This section describes a StateMachine that can be deployed as part of a system designed and used to reflect the current state of the system, process, equipment or item. Customized version of this model can be implemented for any system, this sample is just an illustration.
The current state from the StateMachine is applied to all items in the HasNotifier hierarchy below the object with which the StateMachine is associated. The SystemState StateMachine can be used to automatically disable, enable, suppress or un-suppress Alarms related to the Object (with in the hierarchy of alarms from the given object). The StateMachine can also be used by advanced alarming software to adjust the setpoint, limits or other items related to the Alarms in the hierarchy.
Optionally, multiple SystemState StateMachines can be deployed.
Figure F.1 – SystemState transitions