Figure 27: Default values and initial value in SysML

The Dependency in the following is for illustration only, to show how an InstanceSpecification b0:B assigned as the defaultValue of b:B within block A carries the "initial values" override for val:Real.

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SysPhS-1.1: 'SysML default and initial values correspond to start values of Modelica components. Start values are marked as fixed, requiring the values be set at the beginning of the simulation (otherwise, simulators only take the values as suggestions ...)'

SysPhS-1.1: 'The following Modelica code corresponds to Figure 15 [ERROR]. It has a model B with a val component. The val component has a start value of 10. A class A is defined with a component b of type B. A component modification indicates that the start value of b.val is 20.0.'

SysPhS-1.1: p.44: 10.10.3 Modelica modeling: Reference to 'The following Modelica code corresponds to Figure 15' should probably be 'to Figure 27'.


model B
  Real val(start = 10.0, fixed = true);
  end B;
model A
  B b(val.start = 20.0, val.fixed = true);
end A;

Export of block A to Modelica from the MagicDraw SysML Plugin or Magic Cyber-Systems Engineer^® (Cameo Systems Modeler^®) gives:


model A
  A _A;
  model A
    B b(val.start=20.0,val.fixed=true);
  end A;
  model B
    Real val(start=10.0,fixed=true);
  end B;
end A;

To learn more about SysML initial values (a.k.a. context-specific values) visit also this separate trail: 08:04: Deep configuration using SysML context-specific values

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Figure 28: Units in SysML

Notes

[ASSERTION, NAMING, WARNING] The SysML block compartment name 'initialValues' for what are really "context-specific values" is confusing - even completely misleading; please just think of them as 'contextValues' (and initial values as a special context case)

[ISSUE]{INFORMATIVE} SysPhS-1.1: p.44: 10.10.3 Modelica modeling: Reference to 'The following Modelica code corresponds to Figure 15' should probably be 'to Figure 27'.

Snippets (quotes/extracts)

[SysML-1.6] A compartment with a label of “initialValues” may be used to show values of properties belonging to a containing block. These values override any default values that may have been previously specified on these properties on their originally defining block

[SysPhS-1.1] SysML default and initial values correspond to start values of Modelica components. Start values are marked as fixed, requiring the values be set at the beginning of the simulation (otherwise, simulators only take the values as suggestions ...)

[SysPhS-1.1] The following Modelica code corresponds to Figure 15 [ERROR].

[SysPhS-1.1] It has a model B with a val component. The val component has a start value of 10. A class A is defined with a component b of type B. A component modification indicates that the start value of b.val is 20.0.

Visit also

SysPhS-1.1