You add a trend log series to a trend chart to compare trend data from different logs or variables.
In WebStation, in the System Tree pane, select the trend chart you want to add a trend log series to.
On the Trend Chart toolbar, click the Add button
In the Select object dialog box, do one of the following:
Click Browse to browse the system to find the schedules you want to add.
Click Object matching type , to get a list of all schedules in the system that can be added.
Click OK .
Click Save .