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With this button historical events can be activated (provided that they are pre-configured). They will be displayed in the same graph to enable a comparison with the actual timeseries. Further explanation is given below.
Display time
To change the view period in the graph, the field Display time in the Status Bar below the graph should be double clicked. The display time can now be changed with help of the menu. Press [OK ] to accept the changed view period. The next time the chart is opened the original configured display time will be used again.
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