Reading or Writing FRAMME using FME

When you undertake a data translation using FME, FME builds a posting script in the form of an FME Workspace (or Mapping File). The posting script controls the mapping of the source to destination format schemas. For the vast majority of formats that FME supports, FME can automatically generate the FME posting script with little or no intervention from the user. FME can extract all the geometry and attribute information for each table or feature type in the source dataset, and make a reasonable guess at how this data should be represented in the destination dataset. The posting script can then be fine tuned, either in the FME Workbench, or using an ASCII editor, to get exactly the desired results - for example, changing attribute or table names, adding coordinate transformations, etc.

FME can be used to read FRAMME data but it requires configuration of either the FME Posting Script, or configuration of a FRAMME reader. This is because the FRAMME data is housed in two parts - geometry in the DGN files and attributes in an external database - usually Oracle. However, FRAMME is a rather "loose" format that is uniquely configured for each installation. It's impossible for FME to automatically determine what the attribute schema should be (the location and names of the attribute tables) and how the attribute records relate to the DGN files. It is worth noting that MGE, which has a similar data structure to FRAMME (DGN plus attribute database), can be read directly because GeoGraphics (MGE) databases always have FEATURE & CATALOG tables and FME can automatically create the necessary linkages between the DGN features and their corresponding attribute records in the database.

Anyway, the upshot of this is that to read FRAMME data you have to manually configure FME. This is done in one of two ways:

  1. Generate a DGN to "destination" FME Mapping File or workspace and then add FME Joiner transformers to the Workspace (or @Relate functions to the mapping file) to read the FRAMME attributes in the associated database.
  2. Use the FME Data Source to create a custom FRAMME reader. This reader will be specific to the FRAMME dataset that it was designed for. This is the preferable approach for a mature FRAMME installation which is unlikely to change in the short term. Once the custom FRAMME reader has been configured, any of the FME applications (Universal Viewer, Workbench, Universal Translator) can be used to view or translate the FRAMME data to another format.

The process is similar when writing to FRAMME, except you also have to define how the DGN "framme" linkages are constructed in the destination DGN file. In fact, this isn't to different to writing external attribute data associated with any DGN file. We have a FAQ on our web site that describes this for Shape to DGN. There is no custom writer at this time. In some cases it may be preferable to use the SEF writer as FME does not support the writing of some of the proprietary DGN elements required by some FRAMME implementations.

The main problem is interpreting the FRAMME linkages correctly. The building of the table relationships is straight forward, it just requires a bit of time to work through it. How much effort is required depends on several things: the complexity of the FRAMME schema; the quality or the FRAMME data model documentation; the requirements of the destination format.

Our Professional Services group is available to help develop a prototype set of FME posting scripts or a custom FRAMME reader to speed-up the knowledge transfer. Alternatively, we can offer a turn-key solution with a deliverable of posting scripts that the user can then run to extract the FRAMME data. Our Professional Services team has considerable experience in extracting FRAMME data as well as determining the structure of the FRAMME data model.

It should be born in mind that if the FRAMME attributes are in a relational database, it may not be necessary to translate the FRAMME attributes at all. If the destination format is one that can also link to the FRAMME attribute database (e.g. Oracle Spatial, ArcSDE, MapInfo, DWG with external attributes), then you may be able to translate the DGN geometry and linkages, and then create a view that links the spatial data to the original FRAMME attribute tables.

Please contact us to find out how Safe Software can help customize a solution to meet your needs.