Structural Design
User Guide
SDNF Export/Import
:
Technical Information
: Issues
Issues
The SDNF file format allows only for the transfer of a character descriptor for a Profile or Connection Detail. For a successful data transfer, there needs to be co-ordination between user’s of each package to make sure that the geometric description associated with the catalogue name is identical and that there is a means of correlation between the packages.
In Model, the structural model may contain two views of the data: one view defined by logical connectivity by references to the connecting items; and the physical view defined by the relative location of items. So, while we may logically relate two items, they may not necessarily be physically close to each other. In many external 3D steel detailing packages the means of determining connectivity may be by proximity. Thus, transferring the AVEVA E3D™ model necessarily involves the loss of real connectivity information which is difficult to reconstitute correctly on Import.
The interface is output a warning message when packets are met which cannot be handled or are unexpected.
The double quote character “ in text fields, particularly in profile spec names is not allowed. The character can cause problems with imperial sized items in the catalogue that use the character to indicate inches. It is not allowed in ANY text fields.
Units
SDNF handles units in a number of ways:
1.
SDNF has a minimal set of unit definitions. ("feet", "meters", "inches","millimeters")
2.
SDNF exports in mm. For example, the units exported in the SDNF file are mm.
3.
SDNF imports all units from SDNF internally. It reads any SDNF file unit (according to the "standard"), but...
4.
SDNF then converts the SDNF input units to mm prior to writing an input "macro", so the model in AVEVA E3D™ is therefore in mm.
5.
To support this, the SDNF environment, switches AVEVA E3D™ to MM DIST, and UNITS DEGREES units prior to export and import.
6.
Because of the way AVEVA E3D™ handles UNITS, the original units cannot be restored to be precisely what they were before.
7.
Therefore, after an export or import transaction, the units are set to MM DIST/MM BORE/UNITS DEGREES.
The SDNF interface attempts to keep the behaviour of the system as consistent as possible across versions of AVEVA E3D™. Holes are always imported as NXTR elements because SDNF does not do any shape recognition. A possible issue in exporting a model and re-importing can occur. While a secondary PLOO would represent a hole, this would have to be represented on import as a negative extrusion, NXTR. So round tripping data causes secondary PLOO elements as well as other negative primitives, to be converted to NXTR elements.
When importing into an empty area and using the "Import Packet 10 as GENSECs" option, Packet 10 (straight members) may not be converted to GENSECS. The issue often occurs with a file that was previously exported from another AVEVA E3D™ model. The :SDNFEMARK attribute on the imported element may refer to an element with the same database reference number in the current model. Do not use the option to convert all Packet 10 members into GENSECs when importing a SDNF file containing elements that originated in AVEVA E3D™.
1974 to current year.
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