The ConfirmationStateMachineType is used to prove a valid Client – Server connection after a restart of the OPC UA Server. This supports the confirmation option of 8.3.4.9.

If several instances of this state machine are provided on a device (due to several instances of the SoftwareUpdateType), all instances should behave as if it is only a single instance. In particular it is sufficient to call one of the confirm methods after reboot.

The ConfirmationStateMachineType is illustrated in Figure 52 and Figure 53 and formally defined in Table 83. The transitions are formally defined in Table 85.

image055.png

Figure 52 – Confirmation state machine

image056.png

Figure 53 – ConfirmationStateMachineType

Table 83 – ConfirmationStateMachineType

Attribute

Value

BrowseName

ConfirmationStateMachineType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the FiniteStateMachineType defined in OPC 10000-5.

HasComponent

Method

Confirm

Mandatory

HasComponent

Variable

ConfirmationTimeout

Duration

BaseDataVariableType

Mandatory

HasComponent

Object

NotWaitingForConfirm

InitialStateType

HasComponent

Object

WaitingForConfirm

StateType

HasComponent

Object

NotWaitingForConfirmToWaitingForConfirm

TransitionType

HasComponent

Object

WaitingForConfirmToNotWaitingForConfirm

TransitionType

Conformance Units

DI SU Update Confirmation

The component Variables of the ConfirmationStateMachineType have additional Attributes defined in Table 84.

Table 84 – ConfirmationStateMachineType Attribute values for child Nodes

BrowsePath

Value Attribute

NotWaitingForConfirm

0:StateNumber

1

WaitingForConfirm

0:StateNumber

2

NotWaitingForConfirmToWaitingForConfirm

0:TransitionNumber

12

WaitingForConfirmToNotWaitingForConfirm

0:TransitionNumber

21

Table 85 – ConfirmationStateMachineType TargetBrowsePath

SourceBrowsePath

Reference Type

Is Forward

TargetBrowsePath

Transitions

NotWaitingForConfirmToWaitingForConfirm

FromState

True

NotWaitingForConfirm

ToState

True

WaitingForConfirm

HasEffect

True

TransitionEventType

WaitingForConfirmToNotWaitingForConfirm

FromState

True

WaitingForConfirm

ToState

True

NotWaitingForConfirm

HasEffect

True

TransitionEventType

The ConfirmationTimeout may be set by a Client to a value other then 0 to enable the confirmation feature. If the value is not 0 and the ClientServer connection is lost, the ConfirmationTimeout represents the maximum time that the Client may need to reconnect and call the Confirm Method. The Server shall automatically reset the value to 0 when the installation is complete.

After a reboot and with a ConfirmationTimeout other than 0 a Client shall call this Method to inform the Server that it has successfully reconnected. If this Method is not called after a lost connection the Server shall regard the update as unsuccessful and shall revert it. A Client needs to react within the time specified in the ConfirmationTimeout Variable.

Signature

Confirm();