Creating and exporting FMU

The Functional Mock-up Interface (ref. [1] and [2]) specifications define two types of software components called Functional Mock-up Units:

• an FMU for Model Exchange is a standardized container for a computer software in binary format that evaluates the differential equations of a system-simulation model. It is aimed at being interfaced with an FMI for Model Exchange compliant simulator which provides at least a numerical solver needed for performing the transient simulation of the model;

• a slave FMU for Co-simulation is a standardized container for a computer software called a simulator that is made of a system-simulation model, mathematical libraries and a numerical solver. It is aimed at being interfaced with a master FMI for Co-simulation simulator which provides at least a co-simulation stepping scheme needed for operating the slave simulator.

Simcenter Amesim is able to create both types of FMU using a single tool called the FMU export assistant. It is based upon a standard interface block which operates on full Simcenter Amesim models, made of submodels connected in a sketch. It automatically translates the description of a model (i.e. its input and output variables, local and global parameters, and internal variables) into an equivalent FMI-standardized model description which wraps:

• the solver and simulator initialization and stepping functions in the co-simulation case;

• the initialization and evaluation functions of the model in the model exchange case.

Functional Mock-up Units are platform-dependent software components. Once created, an FMU contains either source files or a binary file called a dynamic link library (for Windows platforms) or a shared library (for Unix platforms) that can be used by an FMI software environment running on the exact same combination of CPU type, architecture and operating system. Since an FMU may contain several binary files corresponding to different platforms, Simcenter Amesim can create an FMU that is compatible with different architectures (32 bit or 64 bit) of the same platform. For a list of supported platforms, refer to Supported platforms.