How to
Assigning a Series to a Y-Axis
You assign a trend chart series to a y-axis to make the chart easier to read. When using two axes, you can set different y-axis scales for the series.
The x-axis of the trend chart represents time. The time span of the axis can be set with a fixed start and end time or with an end time relative to the present time. The axis can be quick-scaled to show the last hour, last day, last month, or last year.
Absolute time span and relative time span, schematic
The y-axis refers to the measurement unit that the variable represents. The scale of the y-axis can be set manually or by auto scale. You can configure the trend chart to present series on one y-axis or two y-axes, one to the left and one to the right. Use two y-axes to present series with different ranges in the same trend chart.
One y-axis and two y-axes, schematic
To make reading easier, grid lines can be shown in the trend chart. Grid lines can be shown in both the x- and y-direction, independent of each other.
Grid lines, schematic
In WorkStation, in the System Tree pane, select the trend chart you want to configure.
On the Trend Chart toolbar, click the Open trend chart settings button
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Click the Series tab.
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In the Data series box, select the series you want to assign to either the left or the right axis.
In the Assigned to y-axis box, select an axis.
Click OK .
The series is now assigned to the left or right y-axis.
Trend Chart Axes
Manually Configuring the Y-Axis Scale
Automatically Configuring the Y-Axis Scale
Trend Chart Event Icons
Trend Chart Settings Dialog Box – Series Tab