Reference

OpcShelvedStateMachineNode Class

Namespace

Opc.UaFx

Assembly

Opc.UaFx.Advanced.dll

Package

Opc.UaFx.Advanced v2.59.0

Members

OpcShelvedStateMachineNode Members

Defines a specialization of the OpcFiniteStateMachineNode which implements a sub-state machine that represents an advanced alarm filtering model.

Syntax

public class OpcShelvedStateMachineNode : OpcFiniteStateMachineNode

Public Class OpcShelvedStateMachineNode
    Inherits OpcFiniteStateMachineNode

Inheritance

Object → OpcNode → OpcInstanceNode → OpcObjectNode → OpcStateMachineNode → OpcFiniteStateMachineNode → OpcShelvedStateMachineNode

Implements

• IOpcNode
• IOpcNodeInfo
• IOpcStateMachine

Remarks

The state model supports two types of Shelving: OneShotShelving and TimedShelving. This includes the allowed transitions between the various sub-states. Shelving is an operator initiated activity.

In OneShotShelving, a user requests that an alarm be shelved for its current active state. This type of shelving is typically used when an alarm is continually occurring on a boundary (i.e. a condition is jumping between high alarm and high high alarm, always in the active state). The one shot shelving will automatically clear when an alarm returns to an inactive state. Another use for this type of shelving is for a plant area that is shutdown i.e. a long running alarm such as a low level alarm for a tank that is not in use. When the tank starts operation again the shelving state will automatically clear.

In TimedShelving, a user specifies that an alarm be shelved for a fixed time period. This type of shelving is quite often used to block nuisance alarms. For example, an alarm that occurs more than 10 times in a minute may get shelved for a few minutes.

In all states, the Unshelve can be called to cause a transition to the unshelve state; this includes un-shelving an alarm that is in the timed shelve state before the time has expired and the one shot shelve state without a transition to an inactive state.

The 'Time Expired' transition is simply a system generated transition that occurs when the time value defined as part of the 'Timed Shelved Call' has expired. The 'Any Transition Occurs' transition is also a system generated transition; this transition is generated when the condition goes to an inactive state.

Constructors

Name	Description
OpcShelvedStateMachineNode6 overloads	Initializes a new instance of the OpcShelvedStateMachineNode class accessible by the name specified.

Properties

Name	Description
DefaultTypeDefinitionIdprotected · override	Gets the default identifier which identifies the node that defines the underlying node type from that this OpcInstanceNode has been created.
OneShotShelveCallback	Gets or sets a callback used to shelve the condition node once.
OneShotShelveNode	Gets the OpcActionMethodNode used to handle 'OneShotShelve' method calls to shelve a condition node once.
TimedShelveCallback	Gets or sets a callback used to shelve the condition node for a specific amount of time.
TimedShelveNode	Gets the OpcTimedShelveMethodNode used to handle 'TimedShelve' method calls to shelve a condition node for a specific amount of time.
UnshelveCallback	Gets or sets a callback used to unshelve the condition node.
UnshelveNode	Gets the OpcActionMethodNode used to handle 'Unshelve' method calls to unshelve a condition node.
UnshelveTime	Gets the remaining time in milliseconds until the alarm automatically transitions into the un-shelved state.
UnshelveTimeNode	Gets the OpcPropertyNode<T> of the UnshelveTime property.

Methods

Name	Description
OneShotShelve	Shelves a condition node once using the context specified.
OneShotShelveCoreprotected · virtual	Shelves a condition node once using the context specified.
TimedShelve	Shelves a condition node for specific amount of time using the context and duration specified.
TimedShelveCoreprotected · virtual	Shelves a condition node using the context and duration information specified.
Unshelve	Unshelves a condition node using the context specified.
UnshelveCoreprotected · virtual	Unshelves a condition node using the context specified.

Inherits members from OpcFiniteStateMachineNode, OpcObjectNode, OpcInstanceNode, OpcNode.

Extension methods

Name	Description
OpcStateMachineNodeExtension.ChangeState	Changes the current state of the stateMachineNode specified using the further specified context.

Applies to

Package	Versions
Opc.UaFx.Advanced	v2.5–v2.59