Report design - Charts

Using the menu option Template/Add data point or Edit data point, you can conveniently define what values of what WinCC OA process variable should be displayed in a row or column. WinCC OA Report then lets you perform calculations (or balance-sheet functions) using formulas applied across these columns or rows of values. The full range of MS Excel functions is available here.

A report can extend over several worksheets of an Excel workbook and thus reflect the logical structure of the data. There is no need to re-enter additional information such as descriptions or aliases, it can be taken directly from WinCC OA.

You can find examples in Daily report from a weather station (Figure) and the report for a Water supply system.

Charts

Charts, trends and graphs can be incorporated both as separate worksheets (as shown in figure) and in the actual rows and columns containing the values (as shown in the Water supply report). All the Excel chart types are available for visualization of WinCC OA process data or values derived from formulas and functions.

Some examples of the basic chart types in Excel are listed below:

  • Bar charts represent figures by bars of corresponding size and are ideal for displaying balance-sheet results (differences, balances).

  • Line charts are ideal for displaying trends and time comparisons.

  • Pie charts can display one set of data at a time, and are suitable for comparing sums or balances. For example, to illustrate the proportional power consumption or energy input.

The primary advantage of Excel charts is that they automatically adopt changes made to values in the worksheet. Secondly, Excel offers numerous chart design options with functions for formatting the chart elements:

  • x-axis units with category label

  • y-axis units

  • Legend (labelling of value sets), for example, data point name from the column titles

  • Chart title, e.g. Trend

  • Axis title (x)

  • Axis title (y)

Time comparisons and trends (line charts)

An Offset function is provided to enable different time ranges from past periods to be compared with one another. Thus by allocating an offset for a data point element, it is possible to retrieve values for a time range other than the one currently created in a report.

It is therefore possible to look at data from earlier periods in one and the same report (Report type setting in the Period field and negative value under Offset), for instance comparing today with yesterday or today with the same day of the previous week.

The following information can be found in the Excel Help

  • How to create charts and use the Chart Wizard,

  • Chart types

  • Chart elements

  • Formatting chart elements

  • Inserting a title

  • Toolbar for editing a chart

  • The Chart menu, Chart context menu

  • Adding a trend line (regression analysis)