The buttons in the Historical Data Viewer page's tool bar enable you to manipulate data to view lesser or greater time periods on the graph in logical increments.
Note: Unlike the Zoom In Y-axis (Analogs Only) and Zoom Out Y-axis (Analogs Only) buttons, the Zoom In X-axis and Zoom Out X-axis buttons work for pens plotting either digital or analog values.
Once you have configured one or more tags to be plotted on the graph on the Historical Data Viewer page (see Add One or More Pens to the Historical Data Viewer Page Using the Tag Selector), follow the instructions below to zoom out and view greater time periods.
1. Click the Zoom Out X-axis button in the Historical Data Viewer page's tool bar. (Note: If you are unable to locate the Zoom Out X-axis button, rest your mouse pointer over the tools in the tool bar to view their names on their associated tooltips.) The mouse pointer changes to display a cross.
2. Click on the graph. The time period will adjust to display the next greater time period, as is reflected by the duration drop-down list and the time scale beneath the graph.
3. Continue to click on the graph until the time period you require has been set.
Note: The maximum time period to which you can zoom out is 5 Years.
The section that follows provides instructions on viewing lesser scale ranges for a pen plotting analog values on the graph.