.NET Based OPC UA Client/Server SDK  3.0.10.493
AcknowledgeableConditionType
Reference NodeClass BrowseName DataType ValueRank TypeDefinition ModellingRule
HasSupertype ObjectType ConditionType  
HasComponent Variable AckedState LocalizedText Scalar TwoStateVariableType Mandatory
HasComponent Method Acknowledge Mandatory
HasComponent Method Confirm Optional
HasComponent Variable ConfirmedState LocalizedText Scalar TwoStateVariableType Optional
HasComponent Variable EnabledState LocalizedText Scalar TwoStateVariableType Mandatory

Extends the ConditionType by defining acknowledgement characteristics. It is an abstract type.

The AcknowledgeableConditionType inherits all Properties of the ConditionType.

AcknowledgeableConditions expose states to indicate whether a Condition has to be acknowledged or confirmed.

The Confirmed Acknowledge model is typically used to differentiate between acknowledging the presence of a Condition and having done something to address the Condition. For example an Operator receiving a motor high temperature Notification calls the Acknowledge method to inform the Server that the high temperature has been observed. The Operator then takes some action such as lowering the load on the motor in order to reduce the temperature. The Operator then calls the Confirm method to inform the Server that a corrective action has been taken.

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. The two states are substates of the TRUE EnabledState. 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. In situations where state changes occur in short succession there can be multiple unacknowledged states and the Server has to maintain ConditionBranches for all previous unacknowledged states. These branches will be deleted after they have been acknowledged or if they reached their final state. Clients are expected to keep track of all ConditionBranches where AckedState is FALSE to allow acknowledgement of those. See also ConditionType for more information about ConditionBranches and the examples in Annex B.1 of Part 9 of the OPC UA Specification. The handling of the AckedState and branches also applies to the ConfirmState.

Variable AckedState

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. Recommended state names for LocaleIds are listed in the following table.

LocaleId FALSE State Name TRUE State Name
en Unacknowledged Acknowledged
de Unquittiert Quittiert
fr Non-acquitté Acquitté

Variable ConfirmedState

Indicates whether the Condition requires confirmation.

Recommended state names for LocaleIds are listed in the following table.

LocaleId FALSE State Name TRUE State Name
en Unconfirmed Confirmed
de Unbestätigt Bestätigt
fr Non-Confirmé Confirmé

Method Acknowledge

Acknowledges an Event Notification for a Condition instance state where AckedState is FALSE.

Normally, the NodeId of the object instance as the ObjectId is passed to the Call Service. However, some Servers do not expose Condition instances in the AddressSpace. Therefore all Servers shall also allow Clients to call the Acknowledge method by specifying ConditionId. The method cannot be called with an ObjectId of the AcknowledgeableConditionType Node.

ResultCode Description
Bad_ConditionBranchAlreadyAcked The EventId does not refer to a state that needs acknowledgement.
Bad_MethodInvalid The method id does not refer to a method for the specified object or ConditionId.
Bad_EventIdUnknown The specified EventId is not known to the Server.
Bad_NodeIdInvalid The node id refers to a node that does not exist in the server address space. Used to indicate that the specified ObjectId is not valid or that the method was called on the ConditionType Node.

Input Arguments

Argument DataType ValueRank Description
EventId ByteString Scalar EventId identifying a particular Event Notification.
Only Event Notifications where AckedState/Id was FALSE can be acknowledged.
Comment LocalizedText Scalar A localized text to be applied to the Condition.

Method Confirm

Confirms an Event Notification for a Condition instance state where ConfirmedState was set to FALSE.

Normally, the NodeId of the object instance as the ObjectId is passed to the Call Service. However, some Servers do not expose Condition instances in the AddressSpace. Therefore all Servers shall also allow Clients to call the Confirm method by specifying ConditionId as the ObjectId. The method cannot be called with an ObjectIf of the AcknowledgeableConditionType Node.

Method Result Codes

ResultCode Description
Bad_ConditionBranchAlreadyConfirmed The EventId does not refer to a state that needs confirmation.
Bad_MethodInvalid The method id does not refer to a method for the specified object or ConditionId.
Bad_EventIdUnknown The specified EventId is not known to the Server.
Bad_NodeIdUnknown The node id refers to a node that does not exist in the server address space. Used to indicate that the specified ObjectId is not valid or that the method was called on the ConditionType Node.

Input Arguments

Argument DataType ValueRank Description
EventId ByteString Scalar EventId identifying a particular Event Notification.
Only Event Notifications where ConfirmedState/Id was TRUE can be confirmed.
Comment LocalizedText Scalar A localized text to be applied to the Conditions.