Auto Update, referred to at the component level as the Refresh Rate, simply means that new data is retrieved at regular intervals. The time interval for the automatic update is configurable. Automatic update can be set at three levels:
At the display level – you can set an automatic update on an entire display. To enable this feature, access Current Display Settings from the Edit menu, click the Auto Update tab and enable the option.
When display-level auto update is enabled, during run-time, the following icon appears on the display:
NOTE: The display-level auto update option can be enabled so that any new display will have auto update enabled by default, depending on the setting on the Time tab of Edit Application Preferences (accessed from the Edit menu | Application Preferences).
At the component level – you can set an automatic update on a component. To enable this feature, access the configuration panel of an object. On the General tab, select the Enable Refresh check box (Enable Auto Refresh for grids) and enter a refresh rate. The Enable Refresh setting is available for grids and the following types of charts: XY, Time, Event, and Correlation.
NOTE: To avoid inaccuracies in the data being presented, when multiple historical data sources are used in expressions, component-level refresh settings are not available.
At the data source level – you can configure options on the data source to allow display level and/or component level automatic updates. See Time Updates on Data Sources for more information.
When both component and display are set up for auto update, the component update has precedence over the display update. In this case, the component will update according to the component's refresh rate setting and the display update will have no effect on it. The display update, however, will have an effect on other objects in the same display that are not set with component-level auto update.
If display auto update is enabled, the scroll and Quick Time controls on both the components and the display are disabled. If component auto update is enabled, only the scroll and Quick Time controls on the component are disabled.
When using a Relational data source, some objects have a default setting that disallows display-level updates. You must change this setting if you want display-level updates to apply to these objects. For example, if you insert a Datalink and configure it with a Relational data source, if you want the Datalink to participate in display-level updates, you must select the Allow Display Updates option from the Advanced Settings dialog box for the Relational data source. For information on how to do this, see To set data source time update options.