Create a calculation based on symbols in a display

To create a calculation from PI AF attribute-based symbols or PI tag-based symbols on a display, perform the following steps:

1. Select the symbol or symbols to include in the calculation. Hold the Ctrl key and click on each symbol.

   

   Note: Selected symbols must be based on either PI tags or AF attributes, but not both.

2. Click Calculations, and then click Add Calculation With Selected Symbols. The number above the icon indicates how many PI tags or AF attributes will be included in the calculation. The number only appears when all symbols on the display, not just the selected symbols, are the same type: either PI tags or AF attributes.

   

3. In the Calculation Editor window, enter a Name and a Description for the calculation.

   Note: The calculation Name needs to be unique for the current display. You may reuse a Calculation Name on different displays.

4. Configure the expression to calculate the data you need, and then click Preview to test the expression with the data currently available.

   

5. Click Advanced Options to further configure the calculation.

6. Configure the Time Interval for the calculation. By default, this is set to Auto, but you can choose a Custom Time Interval if needed.

   If you set the Time Interval to Auto:

   • Set the Total Conversion Factor for the calculation. This only applies to the Total summary Column.

   • Click Stepped Plot to display the calculation with stepped data.

     

     If you set the Time Interval to Custom:

   • Set the Calc Interval for the calculation. The Calc Interval is the time range for which the data calculation is performed.

   • Set the Sync Time for the calculation. The Sync Time is the time of day (in 24-hour format) from which Calc Intervals are counted.

   • Set the Total Conversion Factor for the calculation. The Total Conversion Factor is used as a time basis for time-weighted totals. This only applies to the Total summary Column.

   • Click Stepped Plot to display the calculation with stepped data.

     

     Example of Calc Intervals and Sync Time defined for a calculation:

   • Calc Interval: 10m

   • Sync Time: 00:00:00 (default)

     The calculated value for each interval is plotted at the start of the interval. Since the Sync Time is set as 00:00:00, the start of the interval begins at the top of the hour. Since the Calc Interval is 10m, every 10 minutes, a new value is plotted. In this example, there is a new plotted value at the following timestamps (among many more):

   • 1:00:00

   • 1:10:00

   • 1:20:00

   • 1:30:00

   • 1:40:00

   • 1:50:00

7. When you have finished configuring the calculation, click Save.