The NodeOPCUA API The NodeOPCUA API

  • API Docs for Version: 0.5.4

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    Subscription Class

    Defined in: packages\node-opcua-server\src\server_subscription.js:186
    Module: opcua.server

    The Subscription class used in the OPCUA server side.

    Constructor

    Subscription

    (
    • options
    )

    Defined in packages\node-opcua-server\src\server_subscription.js:186

    Parameters:

    • options Object
      • id Integer
        • a unique identifier
      • publishingInterval Integer
      • maxKeepAliveCount Integer
      • lifeTimeCount Integer
      • publishingEnabled Boolean
      • sessionId NodeId
        • [optional]
      • maxNotificationsPerPublish Integer
      • priority Byte

    Methods

    _addNotificationMessage

    (
    • notificationData
    )

    Defined in packages\node-opcua-server\src\server_subscription.js:914

    Parameters:

    • notificationData ArrayEventNotificationList | StatusChangeNotification>

    _createMonitoredItemStep2

    (
    • timestampsToReturn
    • monitoredItemCreateRequest
    • node
    )
    subscription_service.MonitoredItemCreateResult private

    Defined in packages\node-opcua-server\src\server_subscription.js:1343

    Parameters:

    Returns:

    subscription_service.MonitoredItemCreateResult:

    _popNotificationToSend

    () NotificationMessage

    Defined in packages\node-opcua-server\src\server_subscription.js:969

    Extract the next Notification that is ready to be sent to the client.

    Returns:

    NotificationMessage:

    the Notification to send._pending_notifications

    _publish_pending_notifications *

    () private

    Defined in packages\node-opcua-server\src\server_subscription.js:445

    _publish_pending_notifications send a "notification" event:

    _sendKeepAliveResponse

    () private

    Defined in packages\node-opcua-server\src\server_subscription.js:685

    _tick

    () private

    Defined in packages\node-opcua-server\src\server_subscription.js:589

    acknowledgeNotification

    (
    • sequenceNumber
    )
    StatusCode

    Defined in packages\node-opcua-server\src\server_subscription.js:1053

    Parameters:

    • sequenceNumber Number

    Returns:

    StatusCode:

    adjustSamplingInterval

    (
    • samplingInterval
    • node
    )
    Number | private

    Defined in packages\node-opcua-server\src\server_subscription.js:1151

    adjust monitored item sampling interval

    • an samplingInterval ===0 means that we use a event-base model ( no sampling)
    • otherwise the sampling is adjusted

    Parameters:

    • samplingInterval Object
    • node Object

    Returns:

    Number | :

    discardOldSentNotifications

    () private

    Defined in packages\node-opcua-server\src\server_subscription.js:996

    discardOldSentNotification find all sent notification message that have expired keep-alive and destroy them.

    extract_notifications_chunk extract up to maxNotificationsPerPublish notifications

    (
    • monitoredItems
    • maxNotificationsPerPublish
    )
    Array private static

    Defined in packages\node-opcua-server\src\server_subscription.js:1535

    Parameters:

    • monitoredItems Array
    • maxNotificationsPerPublish Number

      the maximum number of notification to extract

    Returns:

    Array:

    getAvailableSequenceNumbers

    () Integer

    Defined in packages\node-opcua-server\src\server_subscription.js:1038

    returns in an array the sequence numbers of the notifications that haven't been acknowledged yet.

    Returns:

    Integer:

    getMonitoredItem

    (
    • monitoredItemId
    )
    MonitoredItem

    Defined in packages\node-opcua-server\src\server_subscription.js:1410

    get a monitoredItem by Id.

    Parameters:

    • monitoredItemId Number

      the id of the monitored item to get.

    Returns:

    MonitoredItem:

    getMonitoredItems

    (
    • result.serverHandles
    )

    Defined in packages\node-opcua-server\src\server_subscription.js:1422

    getMonitoredItems is used to get information about monitored items of a subscription.Its intended use is defined in Part 4. This method is the implementation of the Standard OPCUA GetMonitoredItems Method.

    Parameters:

    • result.serverHandles Int32

      Array of serverHandles for all MonitoredItems of the subscription identified by subscriptionId. result.clientHandles {Int32[]} Array of clientHandles for all MonitoredItems of the subscription identified by subscriptionId. result.statusCode {StatusCode} from spec: This method can be used to get the list of monitored items in a subscription if CreateMonitoredItems failed due to a network interruption and the client does not know if the creation succeeded in the server.

    increaseKeepAliveCounter

    () private

    Defined in packages\node-opcua-server\src\server_subscription.js:730

    increaseLifeTimeCounter

    () private

    Defined in packages\node-opcua-server\src\server_subscription.js:765

    modify

    (
    • param
    )

    Defined in packages\node-opcua-server\src\server_subscription.js:344

    Parameters:

    • param Object
      • requestedPublishingInterval Duration

        requestedPublishingInterval =0 means fastest possible

      • requestedLifetimeCount Counter

        requestedLifetimeCount ===0 means no change

      • requestedMaxKeepAliveCount Counter

        requestedMaxKeepAliveCount ===0 means no change

      • maxNotificationsPerPublish Counter
      • priority Byte

    notificationHasExpired

    (
    • notification
    )
    Boolean

    Defined in packages\node-opcua-server\src\server_subscription.js:982

    returns true if the notification has expired

    Parameters:

    • notification Object

    Returns:

    Boolean:

    removeMonitoredItem

    (
    • monitoredItemId
    )

    Defined in packages\node-opcua-server\src\server_subscription.js:1476

    remove a monitored Item from the subscription.

    Parameters:

    • monitoredItemId Number

      the id of the monitored item to get.

    resetKeepAliveCounter

    () private

    Defined in packages\node-opcua-server\src\server_subscription.js:714

    resetLifeTimeAndKeepAliveCounters

    ()

    Defined in packages\node-opcua-server\src\server_subscription.js:801

    the server invokes the resetLifeTimeAndKeepAliveCounters method of the subscription when the server has send a Publish Response, so that the subscription can reset its life time counter.

    resetLifeTimeCounter

    () private

    Defined in packages\node-opcua-server\src\server_subscription.js:755

    Reset the Lifetime Counter Variable to the value specified for the lifetime of a Subscription in the CreateSubscription Service( 5.13.2).

    terminate Calling this method will also remove any monitored items.

    ()

    Defined in packages\node-opcua-server\src\server_subscription.js:816

    Terminates the subscription.

    Properties

    disabledMonitoredItemCount

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:1121

    number of disabled monitored items.

    hasMonitoredItemNotifications true if monitored Item have uncollected Notifications

    Boolean

    Defined in packages\node-opcua-server\src\server_subscription.js:1512

    hasPendingNotifications

    Boolean

    Defined in packages\node-opcua-server\src\server_subscription.js:1092

    return True is there are pending notifications for this subscription. (i.e moreNotifications)

    keepAliveCounterHasExpired

    Boolean true if the keep alive counter has reach its limit. private

    Defined in packages\node-opcua-server\src\server_subscription.js:744

    lifeTimeCount

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:244

    The life time count defines how many times the publish interval expires without having a connection to the client to deliver data. If the life time count reaches maxKeepAliveCount, the subscription will automatically terminate. OPCUA Spec: The life-time count shall be a minimum of three times the keep keep-alive count.

    Note: this has to be interpreted as without having a PublishRequest available

    Default: 1

    lifeTimeHasExpired

    boolean - true if the subscription life time has expired.

    Defined in packages\node-opcua-server\src\server_subscription.js:774

    True if the subscription life time has expired.

    maxKeepAliveCount

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:230

    The keep alive count defines how many times the publish interval need to expires without having notifications available before the server send an empty message. OPCUA Spec says: a value of 0 is invalid.

    Default: 10

    maxNotificationsPerPublish

    Number #default 0

    Defined in packages\node-opcua-server\src\server_subscription.js:259

    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 number of notifications per Publish is the sum of monitoredItems in the DataChangeNotification and events in the EventNotificationList.

    monitoredItemCount

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:1112

    number of monitored items.

    monitoredItemIdCounter

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:288

    number of monitored Item

    pendingNotificationsCount - number of pending notifications

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:1083

    publishingInterval

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:222

    the Subscription publishing interval

    Default: 1000

    sentNotificationsCount

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:1103

    number of sent notifications

    timeToExpiration

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:786

    number of milliseconds before this subscription times out (lifeTimeHasExpired === true);

    unacknowledgedMessageCount

    Number

    Defined in packages\node-opcua-server\src\server_subscription.js:1134

    The number of unacknowledged messages saved in the republish queue.

    Events

    "terminated"

    Defined in packages\node-opcua-server\src\server_subscription.js:856

    notify the subscription owner that the subscription has been terminated.

    expired

    Defined in packages\node-opcua-server\src\server_subscription.js:632

    notify the subscription owner that the subscription has expired by exceeding its life time.

    keepalive

    Defined in packages\node-opcua-server\src\server_subscription.js:700

    notify the subscription owner that a keepalive message has to be sent.

    removeMonitoredItem

    Defined in packages\node-opcua-server\src\server_subscription.js:1497

    notify that a monitored item has been removed from the subscription

    Event Payload: