General

General

I try to run a Functional Mock-up Interface (FMI) Co-simulation in CFX. When I try to initialize my Functional Mock-up Unit (FMU) in CFX-Pre, I get an error message “FMUs with String or Enumeration Scalar Variables are not supported.”. What is the reason for this and is there a workaround?

    • FAQFAQ
      Participant

      When trying to initialize an FMU that contains any variables of type “String” or “Enumeration”, the FMU cannot be initialized in CFX-Pre and you’ll get the following error message: ERROR Error reading the FMU file ‘D:/mypath/myFMU.fmu’: FMUs with String or Enumeration Scalar Variables are not supported. This is a documented limitation, see CFX Modeling Guide, chapter 14.2.1. “Limitations of using CFX with FMI”: — * Both integer and logical parameters are represented by real values inside the CFX-Solver, and converted during communication with FMUs. CFX implementation does not support FMU parameters of strings or enumeration types. — It is important to note that with CFX versions up to 2019 R2, this limitation also applies to internal variables of the FMU (that is, variables that are no inputs or outputs, but e.g. constants) of type “String” or “Enumeration” which will never be used or touched by the CFX solver. This will be corrected in CFX 2019 R3, so you will be able to use FMUs with internal variables of type “String” or “Enumeration” and just the input and output variables must be of type “Integer”, “Real”, or “Boolean”. For versions up to 2019 R2, the only workaround is to modify your FMI/FMU model such that it does not use enumeration and string variables anywhere in the model.