The Acknowledgeable Condition Model extends the Condition model. States for acknowledgement and confirmation are added to the Condition model.

AcknowledgeableConditions are represented by the AcknowledgeableConditionType which is a subtype of the ConditionType. The model is formally defined in the following sub clauses.

The AcknowledgeableConditionType extends the ConditionType by defining acknowledgement characteristics. It is an abstract type. The AcknowledgeableConditionType is illustrated in Figure 11 and formally defined in Table 28.

Figure 11 – AcknowledgeableConditionType overview

Table 28 – AcknowledgeableConditionType definition

Attribute	Value
BrowseName	AcknowledgeableConditionType
IsAbstract	False
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
Subtype of the ConditionType defined in clause 5.5.2.
HasSubtype	ObjectType	AlarmConditionType	Defined in Clause 5.8.2
HasComponent	Variable	AckedState	LocalizedText	TwoStateVariableType	Mandatory
HasComponent	Variable	ConfirmedState	LocalizedText	TwoStateVariableType	Optional
HasComponent	Method	Acknowledge	Defined in Clause 5.7.3		Mandatory
HasComponent	Method	Confirm	Defined in Clause 5.7.4		Optional

The AcknowledgeableConditionType inherits all Properties of the ConditionType.

AckedState when False indicates that the Condition instance requires acknowledgement for the reported Condition state. When the Condition instance is acknowledged the AckedState is set to True. ConfirmedState indicates whether it requires confirmation. Recommended state names are described in Annex A. The two states are sub-states of the True EnabledState. See 4.3 for more information about acknowledgement and confirmation models. The EventId used in the Event Notification is considered the identifier of this state and has to be used when calling the Methods for acknowledgement or confirmation.

A Server may require that previous states be acknowledged. If the acknowledgement of a previous state is still open and a new state also requires acknowledgement, the Server shall create a branch of the Condition instance as specified in 4.4. Clients are expected to keep track of all ConditionBranches where AckedState/Id is False to allow acknowledgement of those. See also 5.5.2 for more information about ConditionBranches and the examples in Clause B.1. The handling of the AckedState and branches also applies to the ConfirmedState.

The Acknowledge Method is used to acknowledge an Event Notification for a Condition instance state where AckedState is False. Normally, the NodeId of the object instance is passed as the ObjectId to the Call Service. However, some Servers do not expose Condition instances in the AddressSpace. Therefore, Servers shall allow Clients to call the Acknowledge Method by specifying ConditionId as the ObjectId. The Method cannot be called with an ObjectId of the AcknowledgeableConditionType Node.

Signature

Acknowledge(

[in] ByteString EventId

[in] LocalizedText Comment

);

The parameters are defined in Table 29

Table 29 – Acknowledge parameters

Argument	Description
EventId	EventId identifying a particular Event Notification. Only Event Notifications where AckedState/Id was False can be acknowledged.
Comment	A localized text to be applied to the Condition.

Method result codes in Table 30 (defined in Call Service)

Table 30 – Acknowledge result codes

Result Code	Description
Bad_ConditionBranchAlreadyAcked	See Table 103 for the description of this result code.
Bad_MethodInvalid	The method id does not refer to a method for the specified object or ConditionId.
Bad_EventIdUnknown	See Table 103 for the description of this result code.
Bad_NodeIdInvalid	Used to indicate that the specified ObjectId is not valid or that the Method was called on the ConditionType Node. See OPC 10000-4 for the general description of this result code.

Comments

A Server is responsible to ensure that each Event has a unique EventId. This allows Clients to identify and acknowledge a particular Event Notification.

The EventId identifies a specific Event Notification where a state to be acknowledged was reported. Acknowledgement and the optional comment will be applied to the state identified with the EventId. If the comment field is NULL (both locale and text are empty) it will be ignored and any existing comments will remain unchanged. If the comment is to be reset, an empty text with a locale shall be provided.

A valid EventId will result in an Event Notification where AckedState/Id is set to True and the Comment Property contains the text of the optional comment argument. If a previous state is acknowledged, the BranchId and all Condition values of this branch will be reported. Table 31 specifies the AddressSpace representation for the Acknowledge Method.

Table 31 – Acknowledge Method AddressSpace definition

Attribute	Value
BrowseName	Acknowledge
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
HasProperty	Variable	InputArguments	Argument[]	PropertyType	Mandatory
AlwaysGeneratesEvent	ObjectType	AuditConditionAcknowledge EventType	Defined in 5.10.5

The Confirm Method is used to confirm an Event Notifications for a Condition instance state where ConfirmedState is False. Normally, the NodeId of the object instance is passed as the ObjectId to the Call Service. However, some Servers do not expose Condition instances in the AddressSpace. Therefore, Servers shall allow Clients to call the Confirm Method by specifying ConditionId as the ObjectId. The Method cannot be called with an ObjectId of the AcknowledgeableConditionType Node.

Signature

Confirm(

[in] ByteString EventId

[in] LocalizedTextComment

);

The parameters are defined in Table 32

Table 32 – Confirm Method parameters

Argument	Description
EventId	EventId identifying a particular Event Notification. Only Event Notifications where the Id property of the ConfirmedState is False can be confirmed.
Comment	A localized text to be applied to the Conditions.

Method result codes in Table 33 (defined in Call Service)

Table 33 – Confirm result codes

Result Code	Description
Bad_ConditionBranchAlreadyConfirmed	See Table 103 for the description of this result code.
Bad_MethodInvalid	The method id does not refer to a method for the specified object or ConditionId. See OPC 10000-4 for the general description of this result code.
Bad_EventIdUnknown	See Table 103 for the description of this result code.
Bad_NodeIdUnknown	Used to indicate that the specified ObjectId is not valid or that the Method was called on the ConditionType Node. See OPC 10000-4 for the general description of this result code.

Comments

A Server is responsible to ensure that each Event has a unique EventId. This allows Clients to identify and confirm a particular Event Notification.

The EventId identifies a specific Event Notification where a state to be confirmed was reported. A Comment can be provided which will be applied to the state identified with the EventId.

A valid EventId will result in an Event Notification where ConfirmedState/Id is set to True and the Comment Property contains the text of the optional comment argument. If a previous state is confirmed, the BranchId and all Condition values of this branch will be reported. A Client can confirm only events that have a ConfirmedState/Id set to False. The logic for setting ConfirmedState/Id to False is Server specific and may even be event or condition specific.

Table 34 specifies the AddressSpace representation for the Confirm Method.

Table 34 – Confirm Method AddressSpace definition

Attribute	Value
BrowseName	Confirm
References	NodeClass	BrowseName	DataType	TypeDefinition	ModellingRule
HasProperty	Variable	InputArguments	Argument[]	PropertyType	Mandatory
AlwaysGeneratesEvent	ObjectType	AuditConditionConfirmEventType	Defined in 5.10.7