7 System State & Alarms

7.1 Overview

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.

7.2 HasEffectDisable

The HasEffectDisable ReferenceType is a concrete ReferenceType and can be used directly. It is a subtype of HasEffect.

The semantic of this ReferenceType is to point from a Transition to an Alarm that will be disabled.

If the Reference is to an Object then all Alarms in the HasNotifier hierarchy below that Object are disabled,

If the target is an AlarmType then all instances of that AlarmType in the HasNotifier hierarchy below the Object containing the StateMachine are disabled,

If the target is an Alarm instance then the given Alarm instance is disabled.

The SourceNode of this ReferenceType shall be an Object of the ObjectType TransitionType or one of its subtypes. The TargetNode can be of an Object or AlarmType.

The representation of the HasEffectDisable ReferenceType in the AddressSpace is specified in Table 138

7.3 HasEffectEnable

The HasEffectEnable ReferenceType is a concrete ReferenceType and can be used directly. It is a subtype of HasEffect.

The semantic of this ReferenceType is to point from a Transition to an Alarm that will be enabled.

If the Reference is to an Object then all Alarms in the HasNotifier hierarchy below that Object are enabled,

If the target is an AlarmType then all instances of that AlarmType in the HasNotifier hierarchy below the Object containing the StateMachine are enabled

If the target is an Alarm instance then the given Alarm instance is enabled.

The SourceNode of this ReferenceType shall be an Object of the ObjectType TransitionType or one of its subtypes. The TargetNode can be of any NodeClass.

The representation of the HasEffectEnable ReferenceType in the AddressSpace is specified in Table 139

7.4 HasEffectSuppressed

The HasEffectSuppressed ReferenceType is a concrete ReferenceType and can be used directly. It is a subtype of HasEffect.

The semantic of this ReferenceType is to point from a Transition to an Alarm that will be suppressed.

If the reference is to an Object then all Alarms in the EventNotifier hierarchy below that Object are suppressed,

If the target is an AlarmType then all instance of that AlarmType in the HasNotifier hierarchy below the Object containing the StateMachine are suppressed,

If the target is an Alarm instance then the given Alarm instance is suppressed.

The SourceNode of this ReferenceType shall be an Object of the ObjectType TransitionType or one of its subtypes. The TargetNode can be of any NodeClass.

The representation of the HasEffectSuppressed ReferenceType in the AddressSpace is specified in Table 140

7.5 HasEffectUnsuppressed

The HasEffectUnsuppressed ReferenceType is a concrete ReferenceType and can be used directly. It is a subtype of HasEffect.

The semantic of this ReferenceType is to point from a Transition to an Alarm that will no longer be suppressed.

If the Reference is to an Object then all Alarms in the HasNotifier hierarchy below that Object are removed from being suppressed,

If the target is an AlarmType then all instance of that AlarmType are no longer suppressed below the Object containing the StateMachine,

if the target is an Alarm instance then the given Alarm instance is no longer suppressed. No errors are logged if the Alarm was not suppressed.

The SourceNode of this ReferenceType shall be an Object of the ObjectType TransitionType or one of its subtypes. The TargetNode can be of any NodeClass.

The representation of the HasEffectUnsuppressed ReferenceType in the AddressSpace is specified in Table 141.