Trend log objects monitor a property for a specific object. When the monitored object of a trend log object becomes unresolved, as in when the monitored object is deleted or its name is changed, the Log device object property will revert to the default value and the trend log object will not collect data.
The Trend Viewer displays trend log object data. There are two ways to create a trend log object: from a template or by clicking on any trendable object. Refer to Trend objects for more information.
If a trend log object monitoring one object is changed to monitor a different one in DT or ABT Site after a download, the trend log buffer does not purge automatically. To avoid a mixed state of records that tracks the previously and currently monitored object, write a record count of 0 to purge the buffer. The trend backup will update after 5 minutes or after clicking Save Device.
The buffer will purge automatically if object monitoring is changed in the web interface.