A ConnectionManager is an optional entity that interacts with multiple AutomationComponents to establish Connections between FunctionalEntities. The ConnectionManager can execute on any Server supporting the OPC UA FX Information Model. In the OPC UA FX Information Model, the ConnectionManager is represented by the ConnectionManagerType, which defines functionality and interfaces to manage the establishment of Connections between FunctionalEntities.

Several ConnectionManagers within a network could establish Connections independently of each other. For example, a ConnectionManager on a controller can establish Connections from the controller to its associated IO devices. In contrast, another ConnectionManager on a line controller could establish Connections between FunctionalEntities on the controllers. Figure 9 illustrates possible deployments of a ConnectionManager. It also illustrates ConnectionConfigurationSets, which contain the information needed to establish Connections.

Figure 9 – Examples of ConnectionManager deployments

For a conceptual overview of how Connections are established by a ConnectionManager and the main ObjectTypes used in this process, see 5.5.

This document defines the core functionality of a ConnectionManager with respect to the process of establishing and closing Connections, reporting errors related to it, and the ConnectionConfigurationSets. This document does not define the implementation of a ConnectionManager. It can be implemented as a standalone application that monitors and manages Connections. It can be integrated into a vendor application, which establishes and closes Connections according to the overall application. The vendor application can also monitor the state of established Connections and trigger a re-establishment of Connections.

NOTE For simplicity in this document, we will describe that a ConnectionManager monitors a Connection, with it being understood that this could be some other application.

Connections to be created are part of a ConnectionManager configuration (ConnectionConfigurationSet).

An AutomationComponent and the included FunctionalEntities report the status of Connections that are part of the FunctionalEntity, and Clients can monitor this status. Some ConnectionManagers could provide the following:

• know when to create a Connection,
• respond to an application that knows when to create a Connection.
• respond to external or internal commands.
• monitor the Connections they create.

Possible reasons for monitoring Connection status include:

• An application or ConnectionManager monitors ConnectionEndpoints on AutomationComponents to decide whether it needs to (re)establish or close Connections. For example:
• On startup, it checks if the desired Connections already exist. For Connections that do not exist, it could trigger the establishment processing.
• At runtime, it would check if any Connections were cleaned up (see 5.5.4) or disappeared (e.g. restarted application). If so, it could trigger establishment processing on the Connection.
• It might determine, for application-defined reasons, that a Connection needs to be closed, and it could trigger the close Connection processing.
• Vendor-specific diagnostic applications monitor Connections defined in ConnectionConfigurationSets on a ConnectionManager and the ConnectionEndpoints on AutomationComponents to present comprehensive Connection information to the operator or engineers, including identification information, current status and last error information.

ConnectionManagers can expose capabilities that describe the functionality they provide (see 6.7.2).