DVUpdateInterval Usage

Valid Range

The valid range of update intervals is 1 through 65 seconds. The fastest recommended update interval is 5 seconds.

Missing or Invalid Update Intervals

If the update interval named range is missing or invalid, the update rate of 10 seconds is used.

Creating a Workbook with Several Calculations

If you are creating a workbook with several DeltaV functions, you can reduce the amount of calculations that the workbook performs by putting MS Excel in manual calculation mode.

To use manual calculation,

Select the Files tab then select Options.
In the Excel Options dialog, select Formulas.
In the Calculation options section, select Manual.
Deselect the Recalculate workbook before saving option.
Click OK.

In this mode, each new read function you create calculates, but other existing functions do not. When you are finished adding functions, change the calculation mode back to Automatic, and all the DeltaV read functions will execute.

Update Intervals for Multiple Sheets

If a workbook has DeltaV read functions on more than one sheet, the update interval should only be defined on one of the sheets. All of the sheets use the same update interval. In fact, the DeltaV Function Wizard does not allow you to create two update intervals. For example, if the update interval is already defined on Sheet1 and you define a new update interval on Sheet2 with the DeltaV Function Wizard, the DeltaV Function Wizard moves the update interval named range from Sheet 1 to Sheet 2.

Update Intervals for Multiple Workbooks

If multiple workbooks containing DeltaV functions are open, each workbook must have the update interval defined. For predictable results, all the update intervals should be the same. If the update interval is 5 seconds in each workbook, then updates will occur every 5 seconds in each workbook (assuming data has changed). If there is a different update interval in each workbook, updates will occur at the rate of the active workbook.