Invalid FMU Export: Enumeration without start value and/or invalid combination of "input" and "fixed"

[andreas.nicolai@…]

Hi all,

I noticed that OpenModelica exports enumeration input values for example as follows:

---

<!-- Index of variable = "523" -->

<ScalarVariable

name="Input.flowDirection"
valueReference="20"
description="Allowed flow direction"
variability="fixed"
causality="input"

<Enumeration declaredType="Modelica.Fluid.Types.PortFlowDirection"/>

</ScalarVariable>
---

Importing such an FMU into a Co-Simulation master fails because the master does not have a valid initial value/selection for the enumeration value.

According to the FMI standard, the combination of "input" and "fixed" is invalid, when no initial value is given (see "Functional Mock-up Interface 2.0", July 25, 2014, Page 48 of 126).

I think this should be fixed by providing an initial value/selection for the enumeration.

[Andreas Nicolai <andreas.nicolai@…>]

To be concrete: please add a "start" attribute to the Enumeration tag.

(I don't think there must be an "initial"="exact" attribute for the ScalarVariable tag. Actually, I don't think this would be allowed for causality=input)

[lochel]

Thanks for your report.

[arun3688]

@Andreas Nicolai Can you make a small modelica model which reproduces this problem so that it is easier for us to debug it.

[hauke.hirsch@…]

modelica model of the fmu

[anonymous]

Hi, I've just added the corresponding modelica model. The fmu was created with OMEdit v1.13.2.

[arun3688]

The model is still big to debug the problem, Can you make simple modelica model which reporduces the problem , I have created a small modelica model which does not reproduce the problem, Please have a look into this.

type Enum = enumeration(test1,test2,test3);
model TypeEnumeration
  input Enum et;
  output Enum et1;
  Enum et2(start=Enum.test2,fixed=true);
equation
  et1 = et.test2;
  et2 = Enum.test3;
end TypeEnumeration;

And generating the fmu, gives me the following

   <ModelVariables>                                         
<!-- Index of variable = \"1\" -->                        
<ScalarVariable                                           
  name=\"_D_outputAlias_et1\"                             
  valueReference=\"0\"                                    
  variability=\"discrete\"                                
  causality=\"local\"                                     
  initial=\"calculated\">                                 
  <Enumeration declaredType=\"Enum\"/>                    
</ScalarVariable>                                         
<!-- Index of variable = \"2\" -->                        
<ScalarVariable                                           
  name=\"et\"                                             
  valueReference=\"1\"                                    
  variability=\"discrete\"                                
  causality=\"input\"                                     
  >                                                       
  <Enumeration declaredType=\"Enum\" start=\"0\"/>        
</ScalarVariable>                                         
<!-- Index of variable = \"3\" -->                        
<ScalarVariable                                           
  name=\"et1\"                                            
  valueReference=\"2\"                                    
  variability=\"discrete\"                                
  causality=\"output\"                                    
  initial=\"exact\">                                      
  <Enumeration declaredType=\"Enum\" start=\"2\"/>        
</ScalarVariable>                                         
<!-- Index of variable = \"4\" -->                        
<ScalarVariable                                           
  name=\"et2\"                                            
  valueReference=\"3\"                                    
  variability=\"discrete\"                                
  causality=\"local\"                                     
  initial=\"exact\">                                      
  <Enumeration declaredType=\"Enum$et2\" start=\"2\"/>    
</ScalarVariable>                                         
</ModelVariables>                                         

I see that you are using older version of OpenModelica, you should try to generate the fmus with newer version and see if the problem exists, if not can you make a mininimal modelica example which reproduces the problem

[casella]

Retargeted to 1.17.0 after 1.16.0 release

[casella]

Retargeted to 1.18.0 because of 1.17.0 timed release.

[casella]

Ticket retargeted after milestone closed