A trend chart can either plot values against time or against a selected pen. In an XY Plot, the X axis represents the value of a selected pen.
The time span controls the number of data points shown. For example, if the time span is 20 seconds and the interval is one second, the chart shows up to 20 points. Data points outside of the time span are removed from the display. The time span is included in the trend chart’s title.
Configure the chart style on the General tab of the trend object’s Properties dialog box.