SysPhS-1.1: p.57: Table 11.3.2.5 Mathematical components: Modelica Parameters for the Subtraction row should indicate (k1 and) k2 required to achieve subtraction via Math.Add (or the correct exported values should be explained).

This page identifies a possible issue, inconsistency, concern, error, or bug!
One of the ways Webel IT Australia helps promote tools, technologies, and languages is by donating a lot of time identifying, tracking, and reporting potential issues, in order to help vendors and developers improve the tools and technologies. In some cases, we also offer workarounds and advice for users. All issues tracked on our public site are offered most constructively and with sincerest gratitude to the tool vendors and technology developers.
DISCLAIMER: Vendors do not officially endorse issue analysis by Webel IT Australia.
Icon class
icon_class
far fa-sticky-note
icon_class_computed
far fa-sticky-note
Note kind
ISSUE
Specification keywords
SysPhS-1.1
Modelica keywords
Modelica.Blocks.Math.Add
Modelica.Blocks.Math.Add::k1
Modelica.Blocks.Math.Add::k2
SysPhS Keywords
Real.Mathematical.Subtraction
Keywords
Click on the image to view it full size
Because of this:
SysPhS-1.1: p.57: GOTCHA: Table 11.3.2.5 Mathematical components: Mathematical.Subtraction maps to Math.Add (in Modelica) and Sum (in Simulink)

The SysPhS Real.Mathematical.Subtraction is useless for subtraction against Modelica unless it is supplemented with parameters or constants for k1 and k2 via the Modelica Add, where typically k1=+1.0 and k2=-1.0.

The MagicDraw SysML Plugin and Magic Cyber-Systems Engineer ® (Cameo Systems Modeler®) implementation of the SysPhSLibrary includes k2 but does not constraint it correctly:

MDSysML/Cameo: SysPhSLibrary: GOTCHA: You must set the additional 'k2' parameter for Modelica to be minus to achieve subtraction
One could argue that the specification implies values k1=+1.0 and k2=-1.0 for Modelica, but it would not hurt to make it explicit.
Relates to
11.3 Component behavior - Real.Mathematical
Related notes
[TIP, WARNING] MDSysML/Cameo: SysPhSLibrary: GOTCHA: You must set the additional 'k2' parameter for Modelica to be minus to achieve subtraction
[TIP, WARNING] SysPhS-1.1: p.57: GOTCHA: Table 11.3.2.5 Mathematical components: Mathematical.Subtraction maps to Math.Add (in Modelica) and Sum (in Simulink)
Related notes (backlinks)
Related snippets (extracts)
Visit also
Visit also (backlinks)
External links
https://build.openmodelica.org/Documentation/Modelica.Blocks.Math.Add.html
https://au.mathworks.com/help/simulink/slref/add.html