# Import-/Export-Facility

## Architecture

The general architecture is represented by layers which are combined according to the function. Some levels do also effect lower levels.

- The bottom layer is the database interface EPQ. All DataView functions for reading data from or writing data to the database are based on this.
- The EDB functions build up on the DataView interfaces. A direct access to the EPQ layer is possible in some parts, e.g. in order to carry out structure resolutions.
- The IEF functions employ EDB interfaces as well as DataView interfaces. Data which can not be provided by DataView are read out from the database with the EPQ interface.

IEF itself has several levels with different functionality:

- The bottom layer, the data access layer, offers functions for reading out data from an ASCII file or writing data to an ASCII file. This layer can also be replaced by a database interface or an interprocess communication interface.
- The IEF basic functions are internal functions which make up the functionality of IEF. They cannot be accessed externally.
- The IEF call interface offers functions which can be called up externally (e.g. via LogiView). A userexit concept is also integrated so that it is possible to integrate external functions or decision tables in IEF. The import and export of data from files can be called up with menu functions. Additional interfaces which employ IEF format definitions do exist in order to convert data from a mask into a string and vice versa.
- The MRL functions offer interfaces for automating the export process. It is possible to integrate masks and review processes. A MRL function can combine several IEF exports.

IEF Call functions - Menu functions - LogiView callup - String mask conversion
IEF Basic Functions (Internal functions)
IEF Input/Output Interface - Open/Close - Write -Read