The CDIF Transfer Format

The CDIF Transfer Format is where CDIF has its name from: "CASE Data Interchange Format". The CDIF Transfer Format is capable of representing models in files and thus aid in interchanging models; it is also capable of representing meta-models in files and can thus be used to interchange meta-models.

Example

Here is a brief example using the CDIF Transfer Format:

CDIF,SYNTAX "SYNTAX.1" "02.00.00",ENCODING "ENCODING.1" "02.00.00"
(:HEADER
    (:SUMMARY
        (ExporterName    "The perfect modelling tool")
        (ExporterVersion "01.23a")
        (ExportDate     "1997/06/01")
        (ExportTime      "01:23:45")
        (PublisherName   "Foo B Ar")
    )
)
(:META-MODEL
    ...
    (:SUBJECTAREAREFERENCE DataFlowModel
        (:VERSIONNUMBER "01.00")
    )
    ...
    (SubjectArea NEW001
        (Name "SecurityExtension")
        (Versionnumber "01.00")
        (Description #[This covers security extensions.]#)
    )
    (MetaEntity ME001
        (Name "SecurityClassification")
        (Description #[A classification that ...]#)
        (Type <Kernel>)
    )
    ...
)
(:MODEL
    (DfmProcess 1
       (Name "Process Order")
    )
    ....
    (SecurityClassification 2
        ....
    )
    ....
)

The first line of the transfer identifies the file as being a CDIF file, with a specific syntax (SYNTAX.1 in version 02.00.00) and a specific encoding (ENCODING.1 in version 02.00.00). After some envelope information, the meta-model section defines which Subject Areas of the CDIF Integrated Meta-model are being used during this transfer, and how the CDIF meta-model is extended. This is only necessary for transfers that use a meta-model that is not completely standardized by CDIF. In the above example, the meta-model is extended by a new Subject Area called SecurityExtension.

In the model section, the meta-model defined or referenced in the meta-model section is instantiated to represent the exported model.

Syntax and Encoding

The CDIF architecture supports multiple syntaxes and encodings. This is reflected in the documents describing the CDIF Transfer Format:

• "CDIF Transfer Format: General Rules for Syntaxes and Encodings" defines a set of rules that every CDIF syntax and encoding has to obey.
• "CDIF Transfer Format: Syntax SYNTAX.1" is a standardized CDIF syntax
• "CDIF Transfer Format: Encoding ENCODING.1" is a standardized CDIF encoding

At this point, CDIF has defined one syntax and one encoding. More might be defined in the future.

Standards Availability

The three standards defining the CDIF Transfer Format (General Rules for Syntaxes and Encodings, SYNTAX.1 and ENCODING.1) have been published in 1994 and are available in print and electronically.

Current Work

There is no Transfer Format Working Group active at the moment. Depending on the potential ramifications from the current update of the CDIF Framework, the Framework Working Group might also address potential changes / additions to the CDIF Transfer Format.

Last modified: 97-08-12 by CDIF Webmaster.Copyright (C) 1997 EIA/CDIF. All rights reserved.
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