R2PointDeviceExt (default name Points) is the container for Obix proxy points under an R2ObixClient. It operates as in other drivers; see “About the Points extension” in the Drivers Guide. This component creates and manages a single watch used for all points that are currently read subscribed.
The following slots are unique or have special importance:
-
Watch Interval
How often the client should poll the point watch for changes. See Watch operation summary.
-
Force Update
This action calls forceUpdate on all ObixProxyExts in this subtree.
-
Include Ui Nodes
Either false (default) or true. When left at false, an R2 Points Discovery job does not include Gx objects under the config branch of the lobby. If you wish to include Gx objects, set this to true and perform another Discover.
-
Include Internal Props
Either false (default) or true. When left at false, an R2 Points Discovery job globally omits properties of R2 objects that are typically for internal configuration only (they do not appear in config branch of the lobby). If you wish to include these properties, set this to true and perform another Discover.
See the “R2ObixClient Points” section in the engineering notes document Niagara R2 to NiagaraAX via oBIX. The default and primary view for the Points extension is the ObixPointManager.
Note that a watch is not really “COV.” The basic mechanics of a watch are as follows:
-
The client requests a watch (object) to be created on the server.
-
The client registers (and unregisters) objects included in the server’s watch, using hrefs. The standard subscription mechanism is used on the NiagaraAX client side to select/deselect objects.
-
The client periodically polls the watch on the server at the defined Watch Interval (above).
-
The server returns a list of any changes in the watched items (since the last poll).