Female 0.1" pin header strips - redefinition "ladder" view

The pin feature is in fact here, as a modelling choice, a Port with AggregationKind 'composite' in the PinHeader hierarchy and a reference Property with AggregationKind 'shared' in the PinHeaderRow hierarchy (where row has AggregationKind 'composite').

Notice how with the Association notation here one can't tell that pin is in fact a Port? Some SysML modellers (influenced it seems by some spec examples) use an additional «port» stereotype for such cases, but this is not recommended [wca:wbp]:

The use of an additional «port» keyword on a Port is usually redundant and causes clutter. The use of an additional «port» keyword on a basic Property is an obsolete trick. Please don't imitate it even if you see it in some specification sample diagrams!

We'll see in the next slide how to use the ports listing compartment for this case instead.

All of the blocks shown are abstract. The pin properties are a {union} of the specific pins that will provided for specific boards in concrete sub-blocks.

Note how the row property of PinHeader_0pt1in_F_double is redefined to be the {union} of row1 and row2.

Not every SysML modeller is a fan of such redefinition "ladder" associative-style diagrams. In the next slide we show similar information for the Properties using mostly just compartments.

Up next

Pin header strips for Arduino Mega2560R3 - compartments view

Notes

[PATTERN]{INFORMATIVE} In the Webel recipe for UML/SysML, the pattern of progressive redefinition of end Properties of Associations between progressively more specialised pairs of Blocks at the same level of abstraction is informally called a "redefinition ladder"

[CAPABILITY, FEATURE, TOOL] MagicDraw/Cameo: Supports embedding of one or more Diagrams in another via the Diagram Overview feature. Awesome!

[TIP]{OPTION} UML2/SysML1.x: If AggregationKind 'shared' has meaning to you (and if you use it consistently without contradicting the use of 'composite' aggregation elsewhere in your model) by all means use it. Damn the purists! But it's going to die in SysMLv2 anyway.

[ANTI-PATTERN, MODELLING] The use of an additional «port» keyword on a Port is usually redundant and causes clutter. The use of an additional «port» keyword on a basic Property is an obsolete trick. Please don't imitate it even if you see it in some specification sample diagrams!

Snippets (quotes/extracts)

[SysML-1.6] SysML also supports properties with shared aggregation, as shown by a white diamond symbol on an association.

[SysML-1.6] Like UML, SysML defines no specific semantics or constraints for properties with shared aggregation, but particular models or tools may interpret them in specific ways.

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