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 ReferenceTypes that can be used by a StateMachine to indicate that a specific Effect on Alarms caused by the transition of a StateMachine. StateMachines that describe the state of a process, system or equipment can vary, but an example StateMachine is provided in Annex F.