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.
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.
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.