Compare attributes at different times on same XY plot

You can compare data points from different time periods on the same XY plot. For example, if a process repeats at a particular frequency, you can compare the values from different iterations of the same phase of the process, such as comparing morning startup to afternoon startup. Similarly, you can compare values to an ideal situation, such as a "golden batch" or optimal startup. Follow this procedure to plot additional points that show the same attributes already in an existing XY plot but at a different time.

1. Right-click the XY plot, and then click Configure XY Plot to open the Configure XY Plot pane.

2. For each additional time period that you want plotted, add the paired attributes to the table under Attributes.

   1. Drag the X-axis attribute from the Assets pane to the DRAG TO ADD cell in the X-Axis column.

   2. Drag the Y-axis attribute from the Assets pane to the DRAG TO ADD cell in the Y-Axis column.

   3. Verify the data retrieval methods for the added attributes.

      For consistency, use the same data retrieval methods for comparable paired attributes.

3. Set the time period for each set of paired attributes.

   1. Select the row in the table under Attributes that corresponds to the paired attributes.

   2. Under X Data Options, select the Use Custom Time Range check box.

   3. Specify the time period for the selected paired attributes.

      Enter values in both Start and End.

      • For repeatable processes, select Offset and enter a PI time abbreviation for the time offset that represents the frequency of the process. For example, if a process happens twice a day, then it happens every 12 hours: enter -12h; if a process happens three times a day, then it happens every 8 hours: enter -8h.

      • For a reference process, such as a golden batch, select Time and enter the time when the reference process occurred.

      After you specify a custom time range, AVEVA PI Vision adds an icon to the X-axis label in the table, and a tooltip shows the time range.

      

4. Format each data pair for easy identification in the plot.

   1. Expand the Format section.

      A table lists each paired attribute. An icon marks rows where the time for the paired attribute differs from the display time, and a tooltip shows how the time differs.

      

   2. In the table of attributes, select the row that corresponds to the data pair you want to format.

   3. Set the properties to identify the data pair in the plot.

      For example, you can set color, marker style and color, and lines.