A class that manages a subscription with an OPC UA server. More...

Public Member Functions
	Subscription (Session session)
	Initializes a new instance of the Subscription class. More...

virtual void	Save (IEncoder encoder)
	Saves the Subscription using the specified encoder. More...

virtual void	Load (IDecoder decoder)
	Initializes the Subscription using the specified decoder. More...

virtual void	SaveAll (BinaryEncoder encoder)
	Saves the Subscription using the specified encoder including the revised parameters by the server and the MonitoredItems More...

virtual void	LoadAll (BinaryDecoder decoder)
	Initializes the Subscription using the specified decoder including the revised parameters by the server and the MonitoredItems. More...

void	Create ()
	Creates a new subscription on the server. More...

void	Create (RequestSettings settings)
	Creates a new subscription on the server. More...

IAsyncResult	BeginCreate (RequestSettings settings, AsyncCallback callback, object userData)
	Asynchronously creates a new subscription on the server. More...

void	EndCreate (IAsyncResult result)
	Completes an asynchronous operation to create a subscription. More...

void	Modify ()
	Modifies a subscription. More...

void	Modify (RequestSettings settings)
	Modifies a subscription. More...

IAsyncResult	BeginModify (RequestSettings settings, AsyncCallback callback, object userData)
	Asynchronously modifies a subscription. More...

void	EndModify (IAsyncResult result)
	Completes an asynchronous operation to modify a subscription. More...

void	Delete ()
	Deletes a subscription. More...

void	Delete (RequestSettings settings)
	Deletes a subscription. More...

IAsyncResult	BeginDelete (RequestSettings settings, AsyncCallback callback, object userData)
	Asynchronously deletes a subscription. More...

void	EndDelete (IAsyncResult result)
	Completes an asynchronous operation to delete a subscription. More...

void	Transfer (uint subscriptionId, List< uint > availableSequenceNumbers, RequestSettings settings)
	Transfers the subscription with the specified subscription id. More...

void	Recreate (RequestSettings settings)
	Recreates the subscription. More...

void	Recreate (NamespaceTable oldNamespaceUris, RequestSettings settings)
	Recreates the subscription. More...

List< StatusCode >	CreateMonitoredItems (IList< MonitoredItem > monitoredItems)
	Creates a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items. More...

List< StatusCode >	CreateMonitoredItems (IList< MonitoredItem > monitoredItems, RequestSettings settings)
	Creates a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items. More...

List< StatusCode >	CreateMonitoredItems (IList< MonitoredItem > monitoredItems, TimestampsToReturn timestampsToReturn, RequestSettings settings)
	Creates a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items. More...

IAsyncResult	BeginCreateMonitoredItems (IList< MonitoredItem > monitoredItems, RequestSettings settings, AsyncCallback callback, object userData)
	Asynchronous call to create a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items. More...

IAsyncResult	BeginCreateMonitoredItems (IList< MonitoredItem > monitoredItems, TimestampsToReturn timestampsToReturn, RequestSettings settings, AsyncCallback callback, object userData)
	Asynchronous call to create a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items. More...

List< StatusCode >	EndCreateMonitoredItems (IAsyncResult result)
	Ends an asynchronous operation to create monitored items. More...

List< StatusCode >	ModifyMonitoredItems (IList< MonitoredItem > monitoredItems)
	Modifies monitored items. More...

List< StatusCode >	ModifyMonitoredItems (IList< MonitoredItem > monitoredItems, RequestSettings settings)
	Modifies monitored items. More...

List< StatusCode >	ModifyMonitoredItems (IList< MonitoredItem > monitoredItems, TimestampsToReturn timestampsToReturn, RequestSettings settings)
	Modifies monitored items. More...

IAsyncResult	BeginModifyMonitoredItems (IList< MonitoredItem > monitoredItems, RequestSettings settings, AsyncCallback callback, object userData)
	Asynchronous call to modify monitored items. More...

IAsyncResult	BeginModifyMonitoredItems (IList< MonitoredItem > monitoredItems, TimestampsToReturn timestampsToReturn, RequestSettings settings, AsyncCallback callback, object userData)
	Asynchronous call to modify monitored items. More...

List< StatusCode >	EndModifyMonitoredItems (IAsyncResult result)
	Ends an asynchronous operation to modify monitored items. More...

List< StatusCode >	DeleteMonitoredItems (IList< MonitoredItem > monitoredItems)
	Deletes monitored items. More...

List< StatusCode >	DeleteMonitoredItems (IList< MonitoredItem > monitoredItems, RequestSettings settings)
	Deletes monitored items. More...

IAsyncResult	BeginDeleteMonitoredItems (IList< MonitoredItem > monitoredItems, RequestSettings settings, AsyncCallback callback, object userData)
	Deletes monitored items. More...

List< StatusCode >	EndDeleteMonitoredItems (IAsyncResult result)
	Ends an asynchronous operation to delete monitored items. More...

List< StatusCode >	SetMonitoringMode (MonitoringMode monitoringMode, IList< MonitoredItem > monitoredItems)
	Sets the monitoring mode for a list of monitored items. More...

List< StatusCode >	SetMonitoringMode (MonitoringMode monitoringMode, IList< MonitoredItem > monitoredItems, RequestSettings settings)
	Sets the monitoring mode for a list of monitored items. More...

IAsyncResult	BeginSetMonitoringMode (MonitoringMode monitoringMode, IList< MonitoredItem > monitoredItems, RequestSettings settings, AsyncCallback callback, object userData)
	Asynchronous call to set the monitoring mode for a list of monitored items. More...

List< StatusCode >	EndSetMonitoringMode (IAsyncResult result)
	Ends an ansynchronous operation to set the monitoring mode for moniored items. More...

SetTriggeringResult	SetTriggering (MonitoredItem triggeringItem, IList< MonitoredItem > linksToAdd, IList< MonitoredItem > linksToRemove, RequestSettings settings)
	Change the triggering for a monitored item. More...

IAsyncResult	BeginSetTriggering (MonitoredItem triggeringItem, IList< MonitoredItem > linksToAdd, IList< MonitoredItem > linksToRemove, RequestSettings settings, AsyncCallback callback, object userData)
	Begins a request to change the triggering for a monitored item. More...

SetTriggeringResult	EndSetTriggering (IAsyncResult result)
	Ends a request to change the triggering for a monitored item. More...

NotificationMessage	Republish (uint retransmitSequenceNumber)
	Republish call to get lost notification messages. More...

NotificationMessage	Republish (uint retransmitSequenceNumber, RequestSettings settings)
	Republish call to get lost notification messages. More...

IAsyncResult	BeginRepublish (uint retransmitSequenceNumber, RequestSettings settings, AsyncCallback callback, object userData)
	Asynchronous republish call to get lost notification messages. More...

NotificationMessage	EndRepublish (IAsyncResult result)
	Ends an asynchronous operation to republish lost notification messages. More...

Properties
Session	Session `[get]`
	Gets the session the subscription is associated with. More...

SubscriptionConnectionStatus	ConnectionStatus `[get]`
	Gets the connection status for the subscription. More...

uint	SubscriptionId `[get, set]`
	Gets the subscription id. More...

Object	UserData `[get, set]`
	Gets or sets the user data. More...

TimestampsToReturn	DefaultTimestampsToReturn `[get, set]`
	Gets or sets the default timestamp to return. More...

RequestSettings	DefaultRequestSettings `[get, set]`
	Gets or sets the default request settings for the subscription. More...

double	PublishingInterval `[get, set]`
	Gets or sets the publishing interval (in milliseconds). More...

double	CurrentPublishingInterval `[get, set]`
	Gets the publishing interval (in milliseconds) currently set on the server. More...

double	Lifetime `[get, set]`
	Gets or sets the lifetime (in milliseconds). More...

double	CurrentLifetime `[get, set]`
	Gets the lifetime of the Subscription (in milliseconds) currently set on the server. More...

double	MaxKeepAliveTime `[get, set]`
	Gets or sets the maximum keep alive time (in milliseconds). More...

double	CurrentMaxKeepAliveTime `[get, set]`
	Gets the maximum keep alive time (in milliseconds) currently set on the server. More...

uint	MaxNotificationsPerPublish `[get, set]`
	Gets or sets the maximum number of notifications per publish. More...

uint	CurrentMaxNotificationsPerPublish `[get, set]`
	Gets the maximum number of notifications per publish currently set on the server. More...

bool	PublishingEnabled `[get, set]`
	Gets or sets a value indicating whether publishing is enabled. More...

bool	CurrentPublishingEnabled `[get, set]`
	Gets a value indicating whether publishing is currently enabled on the server. More...

byte	Priority `[get, set]`
	Gets or sets the priority of the subscription. More...

byte	CurrentPriority `[get, set]`
	Gets the priority of the subscription currently set on the server. More...

MonitoredItem[]	MonitoredItems `[get]`
	Gets the monitored items in the subscription. More...

Events
DataChangedEventHandler	DataChanged
	Occurs when any subscribed data value has changed. More...

NewEventsEventHandler	NewEvents
	Occurs when any new event has arrived. More...

SubscriptionStatusChangedEventHandler	StatusChanged
	Occurs when the status of subscription changes. More...

NotificationMessageReceivedEventHandler	NotificationMessageReceived
	Occurs when a new notification message arrives. More...

MissingSequenceNumberEventHandler	MissingSequenceNumber
	Occurs when a sequence number is missing. More...

SubscriptionRecreatedEventHandler	Recreated
	Occurs when a Subscription is automatically recreated after a successful reconnect. More...

Detailed Description

A class that manages a subscription with an OPC UA server.

The approach to create a new subscription on the server is:

create a Subscription object,
change the Subscription settings if necessary,
call Create() to actually create the Subscription on the server.

The Subscription class contains several properties to set or change the settings of the subscription. Note that these parameters come in pairs: [ParameterName] and Current[ParameterName] (e.g. PublishingInterval and CurrentPublishingInterval). The first one is used to set the parameter inside the subscription object before calling Create() or Modify(), the second one reflects the value that is currently set on the server.

Note that some of the subscription settings requested by the client may be revised by the server.

See Subcription Overview and OPC UA Client/Server Subscription Concept for a more general description.

Constructor & Destructor Documentation

UnifiedAutomation.UaClient.Subscription.Subscription ( Session session )

inline

Initializes a new instance of the Subscription class.

The following standard settings are used:

PublishingEnabled: true
PublishingInterval: 500 ms
Lifetime: SessionTimeout
MaxKeepAliveTime: WatchdogTimeout / 2
the DefaultRequestSettings of the Session

Parameters

session The session to associate the subscription with.

Member Function Documentation

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginCreate	(	RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Asynchronously creates a new subscription on the server.

Parameters

settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

Returns: An object which must be passed to the EndCreate method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginCreateMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Asynchronous call to create a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items.

Parameters

monitoredItems	A list of monitored items to create.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

If this method is called before the Subscription is created, the MonitoredItems are saved and the return status is GoodCallAgain. The MonitoredItems will be automatically created after the Subscription is created. Any errors are reported in the LastError property of the MonitoredItem object.

Returns: An object which must be passed to the EndCreateMonitoredItems method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginCreateMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		TimestampsToReturn	timestampsToReturn,
		RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Asynchronous call to create a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items.

Parameters

monitoredItems	A list of monitored items to create.
timestampsToReturn	Indicates whether server and / or source timestamps are returned.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

If this method is called before the Subscription is created, the MonitoredItems are saved and the return status is GoodCallAgain. The MonitoredItems will be automatically created after the Subscription is created. Any errors are reported in the LastError property of the MonitoredItem object.

Returns: An object which must be passed to the EndCreateMonitoredItems method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginDelete	(	RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Asynchronously deletes a subscription.

Parameters

settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

Returns: An object which must be passed to the EndDelete method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginDeleteMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Deletes monitored items.

Parameters

monitoredItems	A list of monitored items to delete.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

Returns: An object which must be passed to the EndDeleteMonitoredItems method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginModify	(	RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Asynchronously modifies a subscription.

Parameters

settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

Returns: An object which must be passed to the EndModify method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginModifyMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Asynchronous call to modify monitored items.

Parameters

monitoredItems	A list of monitored items to modify.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

Returns: An object which must be passed to the EndModifyMonitoredItems method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginModifyMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		TimestampsToReturn	timestampsToReturn,
		RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Asynchronous call to modify monitored items.

Parameters

monitoredItems	A list of monitored items to modify.
timestampsToReturn	OPC UA defines two timestamps, the source and the server timestamp. This parameter allows the client to define which timestamps the server should return with the value. The source timestamp is only available for Value Attributes. The source timestamp is used to reflect the timestamp that was applied to a Variable value by the data source. It should indicate the last change of the value or status code. The source timestamp must be always generated by the same physical clock. This timestamp type was added for OPC UA to cover the use case to get the timestamp of the last value change which is different than the server timestamp definition. The server timestamp is used to reflect the time that the server received a Variable value or knew it to be accurate if the changes are reported by exception and the connection to the data source is operating. This is the behavior expected by Classic OPC Possible values are TimestampsToReturn.Source TimestampsToReturn.Server TimestampsToReturn.Both
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

Returns: An object which must be passed to the EndModifyMonitoredItems method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginRepublish	(	uint	retransmitSequenceNumber,
		RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Asynchronous republish call to get lost notification messages.

Parameters

retransmitSequenceNumber	The sequence number of a notification message to be republished.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

Returns: An object which must be passed to the EndRepublish method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginSetMonitoringMode	(	MonitoringMode	monitoringMode,
		IList< MonitoredItem >	monitoredItems,
		RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Asynchronous call to set the monitoring mode for a list of monitored items.

Parameters

monitoringMode	The new monitoring mode. Possible values are `Disabled`, `Sampling`, and `Reporting`.
monitoredItems	A list of monitored items.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.
callback	The callback to use when the async call completes.
userData	The user data that is passed to the callback.

Returns: An object which must be passed to the EndSetMonitoringMode method.

IAsyncResult UnifiedAutomation.UaClient.Subscription.BeginSetTriggering	(	MonitoredItem	triggeringItem,
		IList< MonitoredItem >	linksToAdd,
		IList< MonitoredItem >	linksToRemove,
		RequestSettings	settings,
		AsyncCallback	callback,
		object	userData
	)

inline

Begins a request to change the triggering for a monitored item.

This method allows to specify items that are reported only when some other item (the triggering item) triggers. This is done by creating links between the triggered items and the items to report.The monitoring mode of the items to report is set to sampling-only so that it will sample and queue Notifications without reporting them.

Parameters

triggeringItem	The monitored item which triggers other monitored items when it reports. This item shall belong to this Subscription.
linksToAdd	The list of monitored items which report when the trigger changes. These MonitoredItems shall belong to this Subscription. The MonitoringMode of these MonitoredItems should be MonitoringMode.Sampling.
linksToRemove	The list of monitored items previously added which should no longer report when the trigger changes.
settings	The settings.
callback	The callback.
userData	The user data.

Returns: The object used to manage the state of the asynchronous operation.

void UnifiedAutomation.UaClient.Subscription.Create ( )

inline

Creates a new subscription on the server.

void UnifiedAutomation.UaClient.Subscription.Create ( RequestSettings settings )

inline

Creates a new subscription on the server.

Parameters

settings The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.CreateMonitoredItems ( IList< MonitoredItem > monitoredItems )

inline

Creates a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items.

Parameters

monitoredItems A list of monitored items to create.

Returns: A list of StatusCodes that indicate for each monitored item whether the CreateMonitoredItem operation has been successful.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.CreateMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		RequestSettings	settings
	)

inline

Creates a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items.

Parameters

monitoredItems	A list of monitored items to create.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

Returns: A list of StatusCodes that indicate for each monitored item whether the CreateMonitoredItem operation has been successful.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.CreateMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		TimestampsToReturn	timestampsToReturn,
		RequestSettings	settings
	)

inline

Creates a list of monitored items in the subscription. The monitored items could be data monitored items or event monitored items.

Parameters

monitoredItems	A list of monitored items to create.
timestampsToReturn	OPC UA defines two timestamps, the source and the server timestamp. This parameter allows the client to define which timestamps the server should return with the value. The source timestamp is only available for Value Attributes. The source timestamp is used to reflect the timestamp that was applied to a Variable value by the data source. It should indicate the last change of the value or status code. The source timestamp must be always generated by the same physical clock. This timestamp type was added for OPC UA to cover the use case to get the timestamp of the last value change which is different than the server timestamp definition. The server timestamp is used to reflect the time that the server received a Variable value or knew it to be accurate if the changes are reported by exception and the connection to the data source is operating. This is the behavior expected by Classic OPC Possible values are TimestampsToReturn.Source TimestampsToReturn.Server TimestampsToReturn.Both
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

Returns: A list of StatusCodes that indicate for each monitored item whether the CreateMonitoredItem operation has been successful.

void UnifiedAutomation.UaClient.Subscription.Delete ( )

inline

Deletes a subscription.

void UnifiedAutomation.UaClient.Subscription.Delete ( RequestSettings settings )

inline

Deletes a subscription.

Parameters

settings The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.DeleteMonitoredItems ( IList< MonitoredItem > monitoredItems )

inline

Deletes monitored items.

Parameters

monitoredItems A list of monitored items to delete.

Returns: A list of StatusCodes that indicate for each monitored item whether the DeleteMonitoredItem operation has been successful.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.DeleteMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		RequestSettings	settings
	)

inline

Deletes monitored items.

Parameters

monitoredItems	A list of monitored items to delete.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

Returns: A list of StatusCodes that indicate for each monitored item whether the DeleteMonitoredItem operation has been successful.

void UnifiedAutomation.UaClient.Subscription.EndCreate ( IAsyncResult result )

inline

Completes an asynchronous operation to create a subscription.

Parameters

result The object returned from the BeginCreate method.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.EndCreateMonitoredItems ( IAsyncResult result )

inline

Ends an asynchronous operation to create monitored items.

Parameters

result The object returned from the BeginCreateMonitoredItems method.

Returns: A list of StatusCodes that indicate for each monitored item whether the CreateMonitoredItem operation has been successful.

void UnifiedAutomation.UaClient.Subscription.EndDelete ( IAsyncResult result )

inline

Completes an asynchronous operation to delete a subscription.

Parameters

result The object returned from the BeginDelete method.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.EndDeleteMonitoredItems ( IAsyncResult result )

inline

Ends an asynchronous operation to delete monitored items.

Parameters

result The object returned from the BeginDeleteMonitoredItems method.

Returns: A list of StatusCodes that indicate for each monitored item whether the DeleteMonitoredItem operation has been successful.

void UnifiedAutomation.UaClient.Subscription.EndModify ( IAsyncResult result )

inline

Completes an asynchronous operation to modify a subscription.

Parameters

result The object returned from the BeginModify method.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.EndModifyMonitoredItems ( IAsyncResult result )

inline

Ends an asynchronous operation to modify monitored items.

Parameters

result The object returned from the BeginModifyMonitoredItems method.

Returns: A list of StatusCodes that indicate for each monitored item whether the ModifyMonitoredItem operation has been successful.

NotificationMessage UnifiedAutomation.UaClient.Subscription.EndRepublish ( IAsyncResult result )

inline

Ends an asynchronous operation to republish lost notification messages.

Parameters

result The object returned from the BeginRepublish method.

Returns: The notification message returned by the server.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.EndSetMonitoringMode ( IAsyncResult result )

inline

Ends an ansynchronous operation to set the monitoring mode for moniored items.

Parameters

result The object returned from the BeginSetMonitoringMode method.

Returns: A list of StatusCodes that indicate for each monitored item whether the SetMonitoringMode operation has been successful.

SetTriggeringResult UnifiedAutomation.UaClient.Subscription.EndSetTriggering ( IAsyncResult result )

inline

Ends a request to change the triggering for a monitored item.

Parameters

result The object used to manage the state of the asynchronous operation.

Returns: The results for each operation to add or remove a link.

virtual void UnifiedAutomation.UaClient.Subscription.Load ( IDecoder decoder )

inlinevirtual

Initializes the Subscription using the specified decoder.

Parameters

decoder The decoder used when initializing the subscription.

virtual void UnifiedAutomation.UaClient.Subscription.LoadAll ( BinaryDecoder decoder )

inlinevirtual

Initializes the Subscription using the specified decoder including the revised parameters by the server and the MonitoredItems.

EXPERIMENTAL: This method is a prototype for a not released feature. The format of the encoded subscription can change in future versions of the sdk. This method cannot be called after Subscription.Create or Session.TransferSubscriptions is called.

Parameters

decoder The decoder used when initializing the subscription.

It is recommended to use the MessageContext of the current Session to create the decoder. The Session must be connected when calling LoadAll.

void UnifiedAutomation.UaClient.Subscription.Modify ( )

inline

Modifies a subscription.

void UnifiedAutomation.UaClient.Subscription.Modify ( RequestSettings settings )

inline

Modifies a subscription.

Parameters

settings The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.ModifyMonitoredItems ( IList< MonitoredItem > monitoredItems )

inline

Modifies monitored items.

Parameters

monitoredItems A list of monitored items to modify.

Returns: A list of StatusCodes that indicate for each monitored item whether the ModifyMonitoredItem operation has been successful.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.ModifyMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		RequestSettings	settings
	)

inline

Modifies monitored items.

Parameters

monitoredItems	A list of monitored items to modify.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

Returns: A list of StatusCodes that indicate for each monitored item whether the ModifyMonitoredItem operation has been successful.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.ModifyMonitoredItems	(	IList< MonitoredItem >	monitoredItems,
		TimestampsToReturn	timestampsToReturn,
		RequestSettings	settings
	)

inline

Modifies monitored items.

Parameters

monitoredItems	A list of monitored items to modify.
timestampsToReturn	OPC UA defines two timestamps, the source and the server timestamp. This parameter allows the client to define which timestamps the server should return with the value. The source timestamp is only available for Value Attributes. The source timestamp is used to reflect the timestamp that was applied to a Variable value by the data source. It should indicate the last change of the value or status code. The source timestamp must be always generated by the same physical clock. This timestamp type was added for OPC UA to cover the use case to get the timestamp of the last value change which is different than the server timestamp definition. The server timestamp is used to reflect the time that the server received a Variable value or knew it to be accurate if the changes are reported by exception and the connection to the data source is operating. This is the behavior expected by Classic OPC Possible values are TimestampsToReturn.Source TimestampsToReturn.Server TimestampsToReturn.Both
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

Returns: A list of StatusCodes that indicate for each monitored item whether the ModifyMonitoredItem operation has been successful.

void UnifiedAutomation.UaClient.Subscription.Recreate ( RequestSettings settings )

inline

Recreates the subscription.

Parameters

settings The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

void UnifiedAutomation.UaClient.Subscription.Recreate	(	NamespaceTable	oldNamespaceUris,
		RequestSettings	settings
	)

inline

Recreates the subscription.

Parameters

oldNamespaceUris	The current NamespaceTable that has been used when the MonitoredItems of the Subscription have been created. If not null and not equal to the current NamespaceTable of the Session, the NodeIds of the MonitoredItems are mapped to use the current NamespaceTable.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

NotificationMessage UnifiedAutomation.UaClient.Subscription.Republish ( uint retransmitSequenceNumber )

inline

Republish call to get lost notification messages.

Parameters

retransmitSequenceNumber The sequence number of a notification message to be republished.

Returns: The notification message returned by the server.

NotificationMessage UnifiedAutomation.UaClient.Subscription.Republish	(	uint	retransmitSequenceNumber,
		RequestSettings	settings
	)

inline

Republish call to get lost notification messages.

Parameters

retransmitSequenceNumber	The sequence number of a notification message to be republished.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

Returns: The notification message returned by the server.

virtual void UnifiedAutomation.UaClient.Subscription.Save ( IEncoder encoder )

inlinevirtual

Saves the Subscription using the specified encoder.

Parameters

encoder The encoder to save the subscription with.

virtual void UnifiedAutomation.UaClient.Subscription.SaveAll ( BinaryEncoder encoder )

inlinevirtual

Saves the Subscription using the specified encoder including the revised parameters by the server and the MonitoredItems

EXPERIMENTAL: This method is a prototype for a not released feature. The format of the encoded subscription can change in future versions of the sdk. The use case for this method is to save a subscription before shutting down the client application. The subscription can be re-initialized and used for Session.TransferSubscriptions.

Parameters

encoder The encoder to save the subscription with.

It is recommended to use the MessageContext of the current Session to create the encoder. The Session must be connected when calling SaveAll.

List<StatusCode> UnifiedAutomation.UaClient.Subscription.SetMonitoringMode	(	MonitoringMode	monitoringMode,
		IList< MonitoredItem >	monitoredItems
	)

inline

Sets the monitoring mode for a list of monitored items.

Parameters

monitoringMode	The new monitoring mode. Possible values are `Disabled`, `Sampling`, and `Reporting`.
monitoredItems	A list of monitored items.

Returns

List<StatusCode> UnifiedAutomation.UaClient.Subscription.SetMonitoringMode	(	MonitoringMode	monitoringMode,
		IList< MonitoredItem >	monitoredItems,
		RequestSettings	settings
	)

inline

Sets the monitoring mode for a list of monitored items.

Parameters

monitoringMode	The new monitoring mode. Possible values are `Disabled`, `Sampling`, and `Reporting`.
monitoredItems	A list of monitored items.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

Returns: A list of StatusCodes that indicate for each monitored item whether the SetMonitoringMode operation has been successful.

SetTriggeringResult UnifiedAutomation.UaClient.Subscription.SetTriggering	(	MonitoredItem	triggeringItem,
		IList< MonitoredItem >	linksToAdd,
		IList< MonitoredItem >	linksToRemove,
		RequestSettings	settings
	)

inline

Change the triggering for a monitored item.

This method allows to specify items that are reported only when some other item (the triggering item) triggers. This is done by creating links between the triggered items and the items to report.The monitoring mode of the items to report is set to sampling-only so that it will sample and queue Notifications without reporting them.

Parameters

triggeringItem	The monitored item which triggers other monitored items when it reports. This item shall belong to this Subscription.
linksToAdd	The list of monitored items which report when the trigger changes. These MonitoredItems shall belong to this Subscription. The MonitoringMode of these MonitoredItems should be MonitoringMode.Sampling.
linksToRemove	The list of monitored items previously added which should no longer report when the trigger changes.
settings	The settings.

Returns: The results for each operation to add or remove a link.

void UnifiedAutomation.UaClient.Subscription.Transfer	(	uint	subscriptionId,
		List< uint >	availableSequenceNumbers,
		RequestSettings	settings
	)

inline

Transfers the subscription with the specified subscription id.

The application is responsible for ensuring that MonitoredItems stored locally match the MonitoredItems that the Server knows about.

Parameters

subscriptionId	The SubscriptionId assigned by the Server.
availableSequenceNumbers	A list of sequence number ranges that identify NotificationMessages that are in the Subscription’s retransmission queue. This parameter is null if the transfer of the Subscription failed.
settings	The general settings for the request. If null, the default settings from the property DefaultRequestSettings are used.

Property Documentation

SubscriptionConnectionStatus UnifiedAutomation.UaClient.Subscription.ConnectionStatus

get

Gets the connection status for the subscription.

double UnifiedAutomation.UaClient.Subscription.CurrentLifetime

getset

Gets the lifetime of the Subscription (in milliseconds) currently set on the server.

See also: Lifetime

double UnifiedAutomation.UaClient.Subscription.CurrentMaxKeepAliveTime

getset

Gets the maximum keep alive time (in milliseconds) currently set on the server.

See also: MaxKeepAliveTime

uint UnifiedAutomation.UaClient.Subscription.CurrentMaxNotificationsPerPublish

getset

Gets the maximum number of notifications per publish currently set on the server.

See also: MaxNotificationsPerPublish

byte UnifiedAutomation.UaClient.Subscription.CurrentPriority

getset

Gets the priority of the subscription currently set on the server.

See also: Priority

bool UnifiedAutomation.UaClient.Subscription.CurrentPublishingEnabled

getset

Gets a value indicating whether publishing is currently enabled on the server.

true if publishing is currently enabled; otherwise, false.

See also: PublishingEnabled

double UnifiedAutomation.UaClient.Subscription.CurrentPublishingInterval

getset

Gets the publishing interval (in milliseconds) currently set on the server.

See also: PublishingInterval

RequestSettings UnifiedAutomation.UaClient.Subscription.DefaultRequestSettings

getset

Gets or sets the default request settings for the subscription.

The default request settings include a timeout, diagnostic settings, request id, and maximum number of operations per request.

TimestampsToReturn UnifiedAutomation.UaClient.Subscription.DefaultTimestampsToReturn

getset

Gets or sets the default timestamp to return.

double UnifiedAutomation.UaClient.Subscription.Lifetime

getset

Gets or sets the lifetime (in milliseconds).

The Lifetime of a Subscription specifies when the Server will close a Subscription due to a lack of Publish requests. This can occur because the Client stops sending Publish requests or because higher priority Subscriptions are consuming all of the available Publish requests. When a Subscription expires, a StatusNotification is returned in the next Publish response to inform the Client that the Subscription is gone.

For convenience this property is defined as time interval in milliseconds. It is internally converted to the UA defined parameter requestedLifetimeCount.

The requested Lifetime may be overridden by the Server. Clients must check the CurrentLifetime property after creating or modifying a Subscription to see the value that the Server will actually use.

See also: CurrentLifetime

double UnifiedAutomation.UaClient.Subscription.MaxKeepAliveTime

getset

Gets or sets the maximum keep alive time (in milliseconds).

MaxKeepAliveTime specifies the maximum time between Publish responses for a Subscription. If no notifications are available, an empty Publish response is returned in order to tell the Client that the Subscription is still alive.

For convenience this property is defined as time interval in milliseconds. It is internally converted to the UA defined parameter requestedMaxKeepAliveCount.

The requested MaxKeepAliveTime may be overridden by the Server. Clients must check the CurrentMaxKeepAliveTime property after creating or modifying a Subscription to see the value that the Server will actually use.

See also: CurrentMaxKeepAliveTime

uint UnifiedAutomation.UaClient.Subscription.MaxNotificationsPerPublish

getset

Gets or sets the maximum number of notifications per publish.

MaxNotificationsPerPublish specifies the maximum number of notifications that the Client wishes to receive in a single Publish response. A value of zero indicates that there is no limit.

The server may send fewer notifications in one message if its own limit is lower.

See also: CurrentMaxNotificationsPerPublish

MonitoredItem [] UnifiedAutomation.UaClient.Subscription.MonitoredItems

get

Gets the monitored items in the subscription.

byte UnifiedAutomation.UaClient.Subscription.Priority

getset

Gets or sets the priority of the subscription.

This setting defines the priority of the subscription relative to other subscriptions created by the client.

A Client that does not require special priority settings should set this value to zero.

See also: CurrentPriority

bool UnifiedAutomation.UaClient.Subscription.PublishingEnabled

getset

Gets or sets a value indicating whether publishing is enabled.

true if publishing is enabled; otherwise, false.

See also: CurrentPublishingEnabled

double UnifiedAutomation.UaClient.Subscription.PublishingInterval

getset

Gets or sets the publishing interval (in milliseconds).

The Publishing Interval specifies the minimum time between Publish responses for a Subscription. Any notifications are buffered by the Server until the Publishing Interval expires. The Server will continue to buffer notifications if no Publish request is available until the Lifetime expires. At this point, the buffered notifications are discarded. Note that the time between Publish responses can be less than the Publishing Interval if the number of notifications exceeds MaxNotificationsPerRequest. However, in this scenario multiple Publish responses are sent as a batch followed by a gap until the PublishingInterval expires again.

The requested PublishingInterval may be overridden by the Server. Clients must check the CurrentPublishingInterval property after creating or modifying a Subscription to see the value that the Server will actually use.

See also: CurrentPublishingInterval

Session UnifiedAutomation.UaClient.Subscription.Session

get

Gets the session the subscription is associated with.

uint UnifiedAutomation.UaClient.Subscription.SubscriptionId

getset

Gets the subscription id.

This property reflects the server-assigned identifier for the subscription. It is unique for the entire server in order to allow the subscription to be transferred to another Session.

See also: ChangeSession(Session)

Object UnifiedAutomation.UaClient.Subscription.UserData

getset

Gets or sets the user data.

Event Documentation

DataChangedEventHandler UnifiedAutomation.UaClient.Subscription.DataChanged

Occurs when any subscribed data value has changed.

This event handler provides the data notification for a subscription.

Data changes may arrive for monitored items before the creation of the monitored items is completed and the CreateMonitoredItems call returns. The client application must be prepared for that and ClientHandles passed in to CreateMonitoredItems must be valid and usable before CreateMonitoredItems returns.

Data changes may also arrive after monitored items are deleted, sampling is turned off, or after the publishing is disabled.

This event handler is normally not called faster than configured in PublishingInterval but this is controlled by the OPC UA Server and not by the client SDK. If the number of notifications in one publishing interval exceeds the setting MaxNotificationsPerPublish, the OPC UA Server will send more than one publish response and this DataChanged may be called more than one time in the PublishingInterval.

If no new data is available in a PublishingInterval, no DataChanged is called and a NotificationMessageReceived event handler with a null data field may be called depending on the property MaxKeepAliveCount.

The DataChanged is called from a worker thread but it should not be blocked by the application since this will block other callbacks like NewEvents contained in the same publish response and also blocks more publish responses received for the same Subscription object.

MissingSequenceNumberEventHandler UnifiedAutomation.UaClient.Subscription.MissingSequenceNumber

Occurs when a sequence number is missing.

The client SDK monitors the sequence numbers of the received data and event notifications and reports gaps in the sequence numbers using this event handler. The client can use the Republish method to request the missing notifications.

The MissingSequenceNumber is called from a worker thread but it should not be blocked by the application since this will block other event handler like DataChanged contained in the same Publish response and also blocks more Publish responses received for the same Subscription object.

NewEventsEventHandler UnifiedAutomation.UaClient.Subscription.NewEvents

Occurs when any new event has arrived.

This event handler provides the event notification for a subscription.

New events may arrive for monitored items before the creation of the monitored items is completed and the CreateMonitoredItems call returns. The client application must be prepared for that and ClientHandles passed in to CreateMonitoredItems must be valid and usable before CreateMonitoredItems returns.

New events may also arrive after monitored items are deleted, sampling is turned off, or after the publishing is disabled.

This event handler is normally not called faster than configured in PublishingInterval but this is controlled by the OPC UA Server and not by the client SDK. If the number of notifications in one publishing interval exceeds the setting MaxNotificationsPerPublish, the OPC UA Server will send more than one publish response and this NewEvents may be called more than one time in the PublishingInterval.

If no new events are available in a PublishingInterval, no NewEvents is called and a NotificationMessageReceived event handler with a null data field may be called depending on the property MaxKeepAliveCount.

The NewEvents is called from a worker thread but it should not be blocked by the application since this will block other callbacks like DataChanged contained in the same publish response and also blocks more publish responses received for the same Subscription object.

NotificationMessageReceivedEventHandler UnifiedAutomation.UaClient.Subscription.NotificationMessageReceived

Occurs when a new notification message arrives.

This event handler provides all notifications for a subscription.

With the this event handler you get access to DataChanged and NewEvents plus control over the Publish sequence number handling. This is mainly necessary if you implement a redundant client and you need access to the sequence numbers and the sequence number confirmation.

Notification messages may arrive for monitored items before the creation of the monitored items is completed and the CreateMonitoredItems call returns. The client application must be prepared for that and ClientHandles passed in to CreateMonitoredItems must be valid and usable before CreateMonitoredItems returns.

Notification messages may also arrive after monitored items are deleted, sampling is turned off, or after the publishing is disabled.

This event handler is normally not called faster than configured in PublishingInterval but this is controlled by the OPC UA Server and not by the client SDK. If the number of notifications in one publishing interval exceeds the setting MaxNotificationsPerPublish, the OPC UA Server will send more than one publish response and this NotificationMessageReceived may be called more than one time in the PublishingInterval.

If no data changes or new events are available in a PublishingInterval, this event handler with a null data field may be called depending on the property MaxKeepAliveCount.

The NotificationMessageReceived is called from a worker thread but it should not be blocked by the application since this will block other callbacks like DataChanged contained in the same publish response and also blocks more publish responses received for the same Subscription object.

SubscriptionRecreatedEventHandler UnifiedAutomation.UaClient.Subscription.Recreated

Occurs when a Subscription is automatically recreated after a successful reconnect.

SubscriptionStatusChangedEventHandler UnifiedAutomation.UaClient.Subscription.StatusChanged

Occurs when the status of subscription changes.

This event handler informs the client if the status of a subscription changes. This can happen after a connection error that lasted longer than the lifetime of the subscription. The lifetime is calculated from PublishingInterval x MaxKeepAliveCount x LifetimeCount. A client must create a new subscription to continue data or event monitoring if this event handler indicates a bad status for the subscription. Subscription.Delete should be called even if the subscription is no longer valid in the server to dispose the client side subscription object.

The documentation for this class was generated from the following file:

D:/work/uasdknet_master/src/UaClient/Subscription.cs

Public Member Functions

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Events

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Constructor & Destructor Documentation

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