Contextualized ad hoc displays

Contextualization for ad hoc displays works by discovering the given number of data items for an asset from the selected asset server and asset database, and plotting the items on the selected symbol type. Up to 10 context tags are shown by default. If the asset you are viewing has more than 10 tags, the first 10 that are listed alphabetically are shown. Showing more than 10 may impact performance.

The current asset is searched in the AF server and AF database, as specified by the Context Asset Server and Context Asset Database properties of the app. If a context server and database are not specified, the default server and database are used.

When the OMI app connects to the AF server and database, it retrieves the top N number of attributes, where N is the number specified by the Max Context Data Item to Show property. The attributes are shown in the selected symbol type.

If a matching asset is not found in the AF server, no data is shown and a message is provided in the System Platform logger.

If the Data Items property is configured, those data items are shown together with the context-driven attributes. The Data Items property can include data items from multiple databases from either the same AF server or a different AF server.

The connection to the Context Asset Server uses the Windows credential of the currently logged-in user.

To contextualize Ad Hoc displays

1. Enable the Follow Current Context property. When Follow Current Context is enabled, you can provide entries for the following properties:

   • Context Asset Server. This property specifies an asset server in your PI system that will be used to get the current context. If you do not enter the server name, the PI Vision OMI app will try to connect to the default asset server. The PI Vision OMI app will use the credentials of the currently logged-in Windows user to connect to the asset server.

   • Context Asset Database: This property names the asset database to retrieve from the specified Context Asset Server, and is used to get the attributes from the currently-selected asset. If a database is not specified, the PI Vision OMI app will attempt to discover the selected asset from the default database of Context Asset Server (if specified). If the Context Asset Server is not specified, it will make the attempt from the default asset server.

2. Set the Max Context Data Items to Show parameter to the number of data items that should be shown from the selected asset. We recommend that you show no more than 10 to ensure good performance.

   The Follow Current Context property will auto-discover the given number of attributes for the selected asset. The attributes of the selected asset are retrieved from the PI Vision AF server and shown in the selected type of symbol at run time. If there is no matching asset found in the AF server, no data is shown, and a message is sent to the System Platform logger.

In addition to contextual data items, you can show data items for other assets, regardless of the current context. These additional data items do not impact the Max Context Data Items to Show property, and do not change as the context changes.