FMU shows parameters that should be hidden

[massimo ceraolo]

Consider model TestFMU below (annotations dropped)

model TestFMU 
  parameter Real K = 1;
  Modelica.Blocks.Interfaces.RealInput u;
  Modelica.Blocks.Interfaces.RealOutput y;
  Modelica.Blocks.Math.Gain gain1(k = K / 2);
Modelica.Blocks.Math.Gain gain(k = 1);
equation
  connect(gain1.u, u);
  connect(gain1.y, gain.u);
  connect(gain.y, y);
end TestFMU;

I exported it as FMU-ME 2.0 and imported into Dymola the parameter window is as in the enclosed file screen.png.
I think the parameter gain1_k shouldn't be visible in the dialog box, since it is internally computed through a binding formula.

[Francesco Casella]

@ceraolo, the binding is not final, so it can still be changed at runtime.

Try with

model TestFMU 
  parameter Real K = 1;
  Modelica.Blocks.Interfaces.RealInput u;
  Modelica.Blocks.Interfaces.RealOutput y;
  Modelica.Blocks.Math.Gain gain1(final k = K / 2);
  Modelica.Blocks.Math.Gain gain(final k = 1);
equation
  connect(gain1.u, u);
  connect(gain1.y, gain.u);
  connect(gain.y, y);
end TestFMU;

[massimo ceraolo]

Two objections to comment 1
1) If @casella is right and the model as written in this ticket's description implies that the parameter gain1.k must be visible from the outside, then we've got a problem with OM: it does not show it! Otherwise it should not appear even when a fmu is created from that model
2) however, even if I add final on binding in gain1:

 Modelica.Blocks.Math.Gain gain1(final k = K / 2);

the fmu still shows this parameter in its dialog box (when imported in Dymola) and this is even more unacceptable.

[Francesco Casella]

Replying to ceraolo:

Two objections to comment 1
1) If @casella is right and the model as written in this ticket's description implies that the parameter gain1.k must be visible from the outside

I didn't write "visible from the outside", I wrote that "it can be changed at runtime". In fact, if you run the original model in OMEdit, you should be able to change all three parameters at run time. Unfortunately, you can only do that for gain.k, not for gain1.k, which is not what I expected.

@Karim, @AnHeuermann, could you check why this happens?

I'm also not sure what is the standard practice with FMU generation. Are you expected to access all the non-final parameters of hierarchically structured models? They could be a lot, but why not?

then we've got a problem with OM: it does not show it! Otherwise it should not appear even when a fmu is created from that model

Show it where, exactly? I'm not sure I understand what you mean here.

2) however, even if I add final on binding in gain1:

 Modelica.Blocks.Math.Gain gain1(final k = K / 2);

the fmu still shows this parameter in its dialog box (when imported in Dymola) and this is even more unacceptable.

I agree. @lochel, would you mind checking why this happens?