Adapter for OPC 10.3 | webMethods Adapter for OPC Documentation | webMethods Adapter for OPC Installation and User's Documentation | Overview of the Adapter | Adapter Listeners and Listener Notification | Listener Notification
 
Listener Notification
A listener notification works in conjunction with a listener to process messages in the Adapter for OPC. When a listener receives a message from the OPC UA server, the listener passes the message to an enabled listener notification that you associated with the listener. For more information about enabling listener notification, see Enabling Listeners.
Note:
The message is lost, if you do not configure any notifications with a listener, or if you do not enable any of the already configured notifications. Software AG recommends that you always start a listener notification before a listener. Create separate listeners to receive notifications of different types. you should configure only one notification per listener. If you configured multiple notifications with a listener, enable only the notification that you require.
When you create a listener notification, Adapter for OPC creates a publishable document type. At run time, after the listener receives a message from the server, the listener invokes the notification. The notification publishes the document created with the notification. A listener notification can publish a document in either of the following ways:
*Publish to a JMS queue or topic when Integration Server is connected to a JMS provider.
*To a local instance of Integration Server when it is not connected to a JMS provider.
When you subscribe to a specific listener notification, a publishable document type is created. You must subscribe to an Integration Server trigger to receive these notifications. For more information about using triggers with services, see the Publish-Subscribe Developer’s Guide.
Note:
To use the JMS protocol with listener notifications, you must first configure a JMS connection alias on Integration Server. For more information, see the webMethods Integration Server Administrator’s Guide.