Learn about trend charts and Preview Results

When you right-click an expression or rollup analysis and select Preview Results, you see the trend chart with input and output attribute values at different trigger times.

If you select Relative to Trigger Time and specify '*-8h' as output time stamp for example, you see two trend charts displayed, one for input and the other for output. The input chart shows the same time range as the configured start and end time; however, the output chart shows the time that is calculated using the output time stamp override to the trigger time. Each trend chart shows a maximum of four input and four output attributes; currently, the input or output attributes that are displayed on the chart are automatically selected by PI Analysis Service.

In the table, the column Output Time indicates the output time calculated with the time stamp override.

Note: The Preview Results charts may depict data that differs from the actual results of the PI Analysis Service. For example, if the same timestamp data is overwritten several times, the Preview Results table and charts show each written value of the data point, but the PI Analysis Service only uses the last written value.