You use a trend log to collect data and then store the records. A record contains a log value or an event as well as its time stamp and an optional comment. A trend log can log an analog variable, a digital variable, or an integer variable.
You create an extended trend log to store log records for a longer period of time and free up memory in the automation server. Extended trend logs are also required for generating reports using EcoStruxure Building Operation WebReports.
You use an extended trend log to store 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 or another extended trend log.
You use the mass create feature to create multiple identical alarms or trend logs for different objects, instead of creating the alarms or trend logs one by one. From trend logs, you can mass create extended trend logs.
The real-time plot is a variable displayed directly in the trend chart. The real-time plot is an instant reflection of the variable, so the history of the real-time plot is lost when the trend chart is closed. However, the history is not lost for I/O points that have implicit logs where approximately 500 records of history are displayed.
You configure the scale of the trend chart axes, the presentation of series, and the calculation method to make it easier to interpret the series, representing the trend log records, in the trend chart.