The update properties determine when and how often an item is updated.
The update properties are grouped into two sections: Sample Settings, and Stale Data Settings. The Stripchart format has and additional setting for the update properties, please refer to the Stripchart chapter for more details.
Sample Settings
The sample mode determines how often data gets sampled. In Real-Time mode the data gets updated every time a new block arrives, this is the most accurate mode since all arriving data will be updated accordingly. You should not enable real-time mode for high frequency items for performance reasons. For once it is hard to visually distinguish quickly updating data and secondly the high update rate will use up CPU resources. Timer mode samples at the given rate and updates when it detects new data. This is the default setting. The shortest sample time is 100ms and it can be increased in 100ms steps. Idle mode updates the display whenever the system is idle and uses the least system resources.
Stale Data Settings
The stale data settings determine how stale data is handled for this item. The global settings can be modified with the View/Options... menu. If you uncheck the "Use global stale data settings" you can override the global settings with your preferences for this item. If you enable stale data notification the item will be marked stale when it does not arrive within the configured timeout. Enabling state data notification on this local level overrides the global setting. When a data item is detected to be stale its display is changed to a crossed out style. The item on the right is the stale version of the one on the left.