Trend extensions - Metasys - LIT-12011953 - Server - Metasys UI - 7.0.50

Metasys UI Help

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Metasys UI
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User Guide
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The trend extension monitors and records the changes in the behavior of an individual attribute over time, thereby assisting you with diagnosing various system-wide behavioral characteristics. The trend extension collects sample values at timed intervals or only upon changes in the given value. Trend data is still collected if the object is unreliable. The trend extension continues to log data using the previous value preceded by ???, which indicates an unreliable status.

For example, use a trend extension to collect data from the Analog Input object of a controller on the N2 Bus, which reports information such as outdoor air temperature or room air temperature.

Trend extensions are different from trend studies. A trend extension collects data samples and records them in its local buffer. For sites with a historical trend repository, trend extensions can be configured to periodically transfer trend data from their local buffer to that repository. When you view a trend extension in Metasys UI, you see only the data that is currently present in the trend extension's local buffer.

Trend studies do not collect any data. Instead, they present data from multiple trends together in a single display. A trend study that is viewed in Metasys UI will include data from trend extension local buffers, as well as data from the site's historical trend repository, if applicable.

Note: Multiple trend extensions can be added to an object for the same or different attributes. However, when an object has multiple trend extensions for the same attribute, the data samples for all of the trend extensions on that same attribute are combined when viewing any one of those trends using a Trend Study.

For trend performance information, refer to the Metasys System Configuration Guide (LIT-12011832).