SysML value Type possible implementation for data type representation

[cecilebraun]

[lfronc]

I updated the plugin development wiki page with notes about the SCADE encoding.

This encoding uses helper types to describe conditional an loop blocks.

We can see that loops are implemented using arrays of 33 elements (N_ITER has length 5 bits). This is problematic because in practice we will not have a full array but an array of size N_ITER.

I guess that we can easily provide a similar representation using SysML datatypes, but the split in different datatypes will produce a model that is harder to read and modify. A packet will be composed of different elements at different location in the model. Using naming conventions while generating the model could help this issue.

EDIT:

Some variables have special values, these values are implemented in SCADE model with enumerations, but if we use SysML enumerations we cannot assign values, this seems not allowed by SysML. Thus I assume that these values will not be generated by Scade system importer.

[cecilebraun]

Waiting for some feedback from @UweSteinkeFromSiemens

[UweSteinkeFromSiemens]

• The enumeration values don’t matter within the model. In contrast to that, the enumeration values are already specified in the ETCS language; this is why we explicitely assigned these values to the enumeration elements in https://github.com/openETCS/dataDictionary/blob/master/Artifacts/subset-026-7/Decoder/Delivery/ScadeStruct/subset-026-7.scade . Therefore, if an explicite assignment of enumeration values should not be possible in SysML, an “enumeration converter” will be required at the external interfaces of ETCS application.
• Dynamic fields are not allowed in dependable and safety related software; this is the reason why SCADE Suite does not support such dynamic fields. Therefore, the dynamic fields as specified in the ETCS language must be replaced by static fields of the appropriate maximum size. Please note, that all arrays must have a statically computable size: otherwise, the transfer to SCADE Suite will fail.

[lfronc]

I pushed the generation of subset 026-7 to the repo and updated the wiki

I have issues in applying a SysML profile (grabbed from papyrus) on the UML model. If somebody knows how to do it, it would be welcome.

[cecilebraun]

@astante @UweSteinkeFromSiemens need to review the model proposition