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
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.
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.
the Subscription publishing interval
number of disabled monitored items.
rue if monitored Item have uncollected Notifications
is 'true' if there are pending notifications for this subscription. (i.e moreNotifications)
True if the subscription life time has expired.
number of monitored items handled by this subscription
number of pending notifications
number of sent notifications
number of milliseconds before this subscription times out (lifeTimeHasExpired === true);
The number of unacknowledged messages saved in the republish queue.
_publish_pending_notifications send a "notification" event:
acknowledges a notification identified by its sequence number
adjust monitored item sampling interval
create a monitored item
address space
the timestamp to return
the parameters describing the monitored Item to create
returns in an array the sequence numbers of the notifications that haven't been acknowledged yet.
get a monitoredItem by Id.
: the id of the monitored item to get.
the monitored item matching monitoredItemId
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. 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.
modify subscription parameters
returns true if the notification has expired
remove a monitored Item from the subscription.
: the id of the monitored item to get.
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.
Reset the Lifetime Counter Variable to the value specified for the lifetime of a Subscription in the CreateSubscription Service( 5.13.2).
set publishing mode
Terminates the subscription. Calling this method will also remove any monitored items.
Generated using TypeDoc
The Subscription class used in the OPCUA server side.