Text Import EIE (TextImport)

The Device Definition Service (DDS) supports the import of data and points using the Text Import driver. This is a useful tool for importing data from an outside source or for bulk tag creation. The source file for an import can be any flat file. The format can be delimited or fixed length.

Imports can be to any current value service (UIS, HSS, OPCIS, or SVCMON). If a current value service is not specified, the data will be written to the CVS that is associated with the DDS in which you have defined the text import device. Data also can be imported into the PNT or the Facility Service.

If you are importing multiple values for a point, the most recent value will reside in the current value service. The other values will be stored in the Value History Service (VHS) if the point is configured to report history.

Imports can be executed on demand from the DDS or scheduled using the Master Scheduling Service (MSS). Once an import is complete, the source files can be deleted from the system or moved to a "processed" directory and retained for a specified number of days. Processed file names are appended with the import completion date/time.

A set of text import statistics points are automatically created for each import device. These points are useful for monitoring the success/failure of imports.

Note: When updating point values (via a value edit in CygNet Explorer, using the TextImport EIE, or via a SetPoint object) all changes are pushed through to the associated CVS (UIS, HSS, and OPCIS). In the case of the OPCIS, you cannot do a text import or a setpoint to an OPCIS point if an external OPC server ID is configured (in the External ID field of the Point reference page of the PNT Editor) because any update is routed back through the external OPC server. This makes it impossible to backfill historical data for a tag that "belongs" to an OPC server.