Set mulitiple Y (vertical) scales for a graph

You can create a graph with a full screen Y scale (axis) for each trend or split the Y scale with up to six individual Y scales. The colors on the Y scales match the colors of the corresponding trend.

If a graph displays more than six trend lines (eight is the maximum), the seventh and eighth trend are displayed on the sixth Y scale. If you use eight trends, it is recommended that you configure items with similar engineering ranges in the last three trends (trends 6, 7, and 8) because any scaling will affect all three trends simultaneously. Display string data values in one of the first five trends.

To create multiple Y scales

  1. Click Chart → Configure Chart to open the Configure Chart dialog. If it is not already selected, click the Configure Chart tab.
    Tip

    Another way to open the Configure Chart dialog is to right-click in the graph area, and then select Configure Chart.

  2. Select the trend for which you want a new Y scale by clicking its check box in the New Axis column. A check mark appears in the check box when the trend is selected.
  3. Click the Multiple Y Axes tab, click the down arrow next to the Axis Styles field, and select a style for how the Y scale is split. For example, if you want:
    • 2 Y scales - select 50/50 in the Axis Styles list
    • 3 Y scales - select 3-Way in the Axis Styles list
    • a full screen Y scale for each trend - select Full Screen. Note Be sure that only one check box is checked in the New Axis column.
    Or, select Manual from the Axis Style list and specify how you want the Y scale split in the % of Y-Axis column.
    Note

    The percentages you enter must total 100% and the number of check marks in the Configure Chart tab must match the number of percentages in the Multiple Y Axes tab.

  4. Click OK to save the changes and close the Configure Chart dialog.
Tip

It is easier to read a graph with multiple Y scales when the Y scales are labeled. Click View → Options, select the Chart Preferences tab, and click Display Y Axis Labels.

Tip

If you specified a Y scale and it is not visible on the graph, open the Configure Chart dialog, select the trend for that Y scale, click Details, and be sure that Show Y-Scale is checked.