Adding external resources and parameter bindings

[Fredrik1Haider]

Hi,

This might be a bug, but more likely just me using the Python api incorrectly (thereby the discussion thread).

I am running omsimulator from 2021-12-26 and noted that my exported SSP contains duplicates of the SSV and SSM I added to the model. What I have done:

• Create model and load FMU
• Export SSM from the model (exportSSMTemplate)
• Modified the SSM
• Generated an SSV from external data
• Used addResources("model", path) for SSV and SSM
  If I export an SSP at this stage there are no parameter bindings in the SSD to the SSV and SSM, thus
• referenceResources(model.root:ssv_path, ssm_path), since there is no references to the SSM and SSV in the SSD prior to this step I am unable to remove any old reference (as recommended in the html doc for referenceResources). It is after this step that the identical duplicates of the SSV and SSM appear in the SSP
• export("model") to get the SSP with the added SSV and modified SSM

Arriving at the following questions:

• Why were the parameter bindings not added, when the resources were added?
• Why does referenceResources add duplicates of the ssm and ssv files?

Best regards

Fredrik

[arun3688]

@Fredrik1Haider It will be good if you can share the python script , so that it is easier to debug, From what you wrote here is an example of referencing new external resources when no prior references are available in ssd https://github.com/OpenModelica/OMSimulator/blob/master/testsuite/api/addExternalResources5.lua , This is a lua script, but it can be adapted to python as well

[Fredrik1Haider]

Thank you for the example! I tested it and got the same results (after converting it to python) as with my implementation (which I am unable to share) and it turns out the issue had nothing to do with OMSimulator, but rather it was a bug with the unarchiver used to view the contents of the exported ssp.

[Matthias776]

@Fredrik1Haider Since I'm facing the same issues right now, I'd like to know if you found a solution for this problem?

[Fredrik1Haider]

Hi @Matthias776, this was quite a while go, but I believe the underlying issue was a mix up of the resources names and paths.
addResources('model', resource_path)
wants the path to the resource, but
referenceResources('resource_in_model')
wants the name of the resource in the model rather than its path. For example when adding the resource "myssv", the input would be "/mypath/myfolder/myssv.ssv", but when adding the reference to the resource the input would instead be "model.root:myssv"

[Matthias776]

Thanks for your quick advice!
The commands are accepted now without an error but, however, when I query the value I changed via the .ssv files, the initial value is still displayed.

In detail, I want change the parameter set of the FMU component controller using config.ssv and config.ssm instead of parametrizing every single variable using oms.setReal("variable")

Like you I requested SSV and SSMTemplates

oms.exportSSVTemplate("model.root.controller", "config.ssv")
oms.exportSSMTemplate("model", "config.ssm")

which I added and referenced to resources after changing parameter values manually

oms.addResources("model", "config.ssv")
oms.addResources("model", "config.ssm")
oms.referenceResources("model.root.controller:config.ssv", "config.ssm")

As a check, I queried the parameter that I've changed manually in the config.ssv file

value, status = oms.getReal("model.root.controller.ratio")
print(value)

but the value hasn't been changed...

My goal is to have several config files with which I can vary parameters for several simulation runs.

[arun3688]

@Matthias776 you have to instantiate the fmu oms.instantiate("model"), so it should be

> oms.addResources("model", "config.ssv")
> oms.addResources("model", "config.ssm")
> oms.referenceResources("model.root.controller:config.ssv", "config.ssm")
> oms.instantiate("model")
> value, status = oms.getReal("model.root.controller.ratio")
   print(value)

see some examples below, these are lua scripts, but you can adapt to python

https://github.com/OpenModelica/OMSimulator/blob/master/testsuite/simulation/referenceResources2.lua
https://github.com/OpenModelica/OMSimulator/blob/master/testsuite/simulation/referenceResources2.lua

[Matthias776]

Works! Thanks a lot both of you!

One further question regarding the handling of parameter sets...
I'd like to structure my composite system into subsystems but fear that it's not possible to get the .ssm and .ssv files by the use of exportSSVTemplate() respectively exportSSVTemplate since their description says that

the function can be called for a top level model or a certain FMU component

Is my assumption correct, so that I have to place all my FMUs in the root system, the top level, model?

[arun3688]

@Matthias776, It is possible to structure into subsystems , but as you said the exportSSVTemplate() functionality does not work on subsystems, but we can implement this, Currently you can use oms_newResources() at different levels and use
oms_exportSnapshot() to get the ssv files which is equal to oms_exportSSVTemplate(), the only difference is oms_exportSnapshot does not export to file, An example would be

from OMSimulator import OMSimulator
oms = OMSimulator()

oms.setCommandLineOption("--suppressPath=true")
oms.setTempDirectory("./subsystem2_py/")

oms.newModel("model")
oms.addSystem("model.root", oms.system_wc)
oms.addSubModel("model.root.sine", "../resources/Modelica.Blocks.Sources.Sine.fmu")

## add resources to submodule
oms.newResources("model.root.sine:sine.ssv")

oms.setReal("model.root.sine.phase", 27)
oms.setReal("model.root.sine.amplitude", -100)
oms.setReal("model.root.sine.freqHz", -300)

## addSubsytem
oms.addSystem("model.root.subsystem", oms.system_sc)
## add component to subsystem
oms.addSubModel("model.root.subsystem.sine1", "../resources/Modelica.Blocks.Sources.Sine.fmu")
oms.newResources("model.root.subsystem.sine1:sine1.ssv")

oms.setReal("model.root.subsystem.sine1.phase", 50)
oms.setReal("model.root.subsystem.sine1.amplitude", 60)
oms.setReal("model.root.subsystem.sine1.freqHz", 70)

oms.setResultFile("model", "")

src, status = oms.exportSnapshot("model:resources/sine.ssv")
print(src)
src, status = oms.exportSnapshot("model:resources/sine1.ssv")
print(src)

Output

<?xml version="1.0"?>                                                                              
<oms:snapshot                                                                                      
  xmlns:oms="https://raw.githubusercontent.com/OpenModelica/OMSimulator/master/schema/oms.xsd"     
  partial="true">                                                                                  
  <oms:file                                                                                        
    name="resources/sine.ssv">                                                                     
    <ssv:ParameterSet                                                                              
      xmlns:ssc="http://ssp-standard.org/SSP1/SystemStructureCommon"                               
      xmlns:ssv="http://ssp-standard.org/SSP1/SystemStructureParameterValues"                      
      version="1.0"                                                                                
      name="parameters">                                                                           
      <ssv:Parameters>                                                                             
        <ssv:Parameter                                                                             
          name="phase">                                                                            
          <ssv:Real                                                                                
            value="27"                                                                             
            unit="rad" />                                                                          
        </ssv:Parameter>                                                                           
        <ssv:Parameter                                                                             
          name="freqHz">                                                                           
          <ssv:Real                                                                                
            value="-300"                                                                           
            unit="Hz" />                                                                           
        </ssv:Parameter>                                                                           
        <ssv:Parameter                                                                             
          name="amplitude">                                                                        
          <ssv:Real                                                                                
            value="-100" />                                                                        
        </ssv:Parameter>                                                                           
      </ssv:Parameters>                                                                            
      <ssv:Units>                                                                                  
        <ssc:Unit                                                                                  
          name="rad">                                                                              
          <ssc:BaseUnit />                                                                         
        </ssc:Unit>                                                                                
        <ssc:Unit                                                                                  
          name="Hz">                                                                               
          <ssc:BaseUnit                                                                            
            s="-1" />                                                                              
        </ssc:Unit>                                                                                
      </ssv:Units>                                                                                 
    </ssv:ParameterSet>                                                                            
  </oms:file>                                                                                      
</oms:snapshot>                                                                                    
                                                                                                   
<?xml version="1.0"?>                                                                              
<oms:snapshot                                                                                      
  xmlns:oms="https://raw.githubusercontent.com/OpenModelica/OMSimulator/master/schema/oms.xsd"     
  partial="true">                                                                                  
  <oms:file                                                                                        
    name="resources/sine1.ssv">                                                                    
    <ssv:ParameterSet                                                                              
      xmlns:ssc="http://ssp-standard.org/SSP1/SystemStructureCommon"                               
      xmlns:ssv="http://ssp-standard.org/SSP1/SystemStructureParameterValues"                      
      version="1.0"                                                                                
      name="parameters">                                                                           
      <ssv:Parameters>                                                                             
        <ssv:Parameter                                                                             
          name="phase">                                                                            
          <ssv:Real                                                                                
            value="50"                                                                             
            unit="rad" />                                                                          
        </ssv:Parameter>                                                                           
        <ssv:Parameter                                                                             
          name="freqHz">                                                                           
          <ssv:Real                                                                                
            value="70"                                                                             
            unit="Hz" />                                                                           
        </ssv:Parameter>                                                                           
        <ssv:Parameter                                                                             
          name="amplitude">                                                                        
          <ssv:Real                                                                                
            value="60" />                                                                          
        </ssv:Parameter>                                                                           
      </ssv:Parameters>                                                                            
      <ssv:Units>                                                                                  
        <ssc:Unit                                                                                  
          name="rad">                                                                              
          <ssc:BaseUnit />                                                                         
        </ssc:Unit>                                                                                
        <ssc:Unit                                                                                  
          name="Hz">                                                                               
          <ssc:BaseUnit                                                                            
            s="-1" />                                                                              
        </ssc:Unit>                                                                                
      </ssv:Units>                                                                                 
    </ssv:ParameterSet>                                                                            
  </oms:file>                                                                                      
</oms:snapshot>