概念
Trend Log Functions
All trend logs store records by using the circular storing principle; you can also connect trends logs to external trend logs with larger storing capacity. For some trend logs you can set up conditions that have to be fulfilled before the trend log starts recording.
Log Record Storage
All trend logs use circular storing. How many records a trend log can store before overwriting old ones depends on the trend log configuration.
有关更多信息，请参阅 日志记录存储 .
Trend Log Activation
The interval trend log and change of value trend log start recording values when the configured activation conditions are met. If an activation variable is used, both the activation variable and the activation time have to be true for the trend log to start recording.
有关更多信息，请参阅 Trend Log Activation .
Extended Trend Logs
You use an extended trend log to transfer records from a trend log. An extended trend log can be connected to a trend log or connected in a series to another extended trend log. Only one extended trend log can be connected to a trend log.
有关更多信息，请参阅 扩展趋势日志 .
Trends Overview
日志记录存储
Trend Log Activation
扩展趋势日志
Viewing Related Trends
Viewing Related Trends for Properties Bound to a Graphic