Using a ShouldPreReadData Registry Key
About this task
ShouldPreReadData
registry key when your calculation tags use AddData
to write to tags that are also used as trigger tags or used in calculation formulas such as CurrentValue("MyTag")+5
.If you want to skip the pre-read of data and have Calculation Collector query data at tag processing time instead, you have to make a registry key on the machine running the Calculation Collector.
Use the following steps to create a value as a DWORD
for ShouldPreReadData
registry key.
Note: This registry key cannot be performed on a Server to Server collector scenario.
Procedure
- From the Start menu, select Run and enter Regedit.
- Open the following key folder HKEY_LOCAL_MACHINE\Software\Intellution, Inc.\iHistorian\Services\CalculationCollector\.
- Create a value as DWORD called
ShouldPreReadData
and set it to zero value (to have the calculation collector skip pre-reading of data, set this value to 0). - Click OK, and close the Registry Editor.
- Restart Calculation Collector for the changes to take effect.