Set behavior for duplicate data values

PI Web API enables you to define preferred system behavior for the treatment of duplicate data values in Data Archive. To define whether new data entries should overwrite previously existing data, complete the following steps:

1. In the System Configuration window, click the Attributes tab.

2. Enter one of the following values for the OmfCreateMode attribute:

   Replace	Adds the value to the archive. If any values exist at the same time, Replace overwrites one of them and set its Substituted flag. Note: We do not recommend using this mode because it skips compression.
   NoReplace	Adds the value to the archive only if no value exists at the same time. If a value already exists for that time, the passed value is ignored.
   Insert	Adds the value to the archive. Any existing values at the same time are not overwritten.