Capabilities and limitations

When exporting a model, three types of FMU are available:

• FMU Model Exchange with binary file format for native platforms and architectures (Windows or Linux)

• FMU for Co-simulation with binary file format for native platforms and architectures (Windows or Linux)

• FMU for Co-simulation with source code for real-time target platforms (dSPACE SCALEXIO, Concurrent SIMulation WorkBench, ETAS LABCAR-OPERATOR, FEV xMOD, Siemens SIMATIC LiveTwin, AVL Testbed.CONNECT and several "generic" 64-bit Linux little endian targets)

Depending on the numerical solver being used to simulate a model in Simcenter Amesim, not all FMI types are available for export. The following table summarizes the permitted combinations:

FMI type available for export	Simcenter Amesim numerical solver required for simulating the model
Variable step size; Explicit system	Fixed step size; Explicit system	Variable step size; Implicit system
Model Exchange (native binary format)
Co-simulation (native binary format)
Co-simulation (real-time target)

The FMI for Co-simulation specifications define optional capabilities that have to be declared by a slave FMU component. The capabilities currently supported by the Export Assistant are the following:

• Variable co-simulation step size is always accepted.

• The FMU does not provide information about events during co-simulation, and does not support event handling.

• Step discarding is not allowed, since the numerical solvers of Simcenter Amesim cannot perform integration steps backwards in time.

• Only synchronous communication is allowed between the environment and the FMU, the stepping functions having a blocking behavior.

• Using multiple instances of the same FMU within the same process is not supported, see section Multiple FMUs and multiple instances of the same FMU for more detail about multiple FMU instances.

• The FMU uses its internal memory allocation functions, not those provided by the environment.

Note

• When exporting FMUs, Simcenter Amesim tunable parameters are automatically mapped to tunable parameters as defined in the FMI specification. If exposed by the FMU, they can then be modified during the simulation within compatible environments.

• Models containing encrypted supercomponents can be exported as FMUs on native platforms (Windows or Linux) only. In particular, this is not supported on real-time targets.

• If an FMU needs to be usable with encrypted table files, the locations of these files need to be defined as supercomponent exposed parameters, and also exposed at the level of the FMU. Then when these files are provided to the end-user with the FMU, he or she can adjust these FMU parameters to correspond to the appropriate locations of the table files on their machine.

• Models containing Modelica blocks or FMI import submodels can be exported as FMU for Co-simulation 1.0, 2.0 or 3.0, or FMU for Model Exchange 2.0, targeting native platforms (Windows or Linux). This is not supported for real-time targets. Moreover, they cannot be exported as FMU for Model Exchange 1.0 in any case.

• User submodels or other kinds of submodel that are not part of the Simcenter Amesim standard libraries are automatically embedded in exported FMUs, except for Real-Time targets for which each of these submodels needs to have its C code declared to be available for export. See section Setting the submodel requirements of the Submodel Editor manual for more detail on these submodel export capabilities. Figure 63: Submodel Editor Export capabilities

Moreover, if the capability No external dependencies required at runtime is declared to be true, then no additional action is required to ensure that the runtime conditions will be met (for example, no environment variables need to be set, no specific tool needs to be installed, no additional binaries need to be provided and so on).

Exportability of models as FMUs

Specific model content	Native binary	Cross-compiled binary1	Source-code / FMU for Real Time
Only submodels from standard native Simcenter Amesim libraries			2
Statecharts
User submodels with sources		3	2
User submodels without sources		Possibly4
Encrypted supercomponents		Possibly4
Modelica blocks
Imported FMUs5		Possibly6
Imported Simulink models (SL2Amecosim)
Submodels with external dependencies (libraries, ...)	7

1. Cross-compilation is currently supported under Windows only for the compilation of "linux64" binaries. This implies that the Linux cross-compiler has been installed with Simcenter Amesim.

2. Export to real-time targets is restricted to standard libraries marked as real-time compatible (see the Real-Time user's guide for the complete list), or to real-time capable user submodels with suitable declared export capabilities. See the Submodel Editor user's guide for more details.

3. Submodel source code is automatically compiled for the desired platform/architecture combination as soon as this is allowed by the declared export capabilities. See the Submodel Editor user's guide for more details.

4. This assumes that compatible compiled objects have been provided by the component supplier i.e., 64-bit Linux objects created with the Linux cross-compiler distributed with Simcenter Amesim. For submodels, such types of compilation can be done using the Submodel Editor or the AMEcc_RELEASE script. For encrypted supercomponents, this can be done using Component Customization.

5. Generally speaking, "FMUs of FMUs" also known as "nested FMUs" only work if imported FMUs are completely standalone (no external dependencies).

6. This works only if all the imported FMUs contain the required compatible “linux64” binaries.

7. This assumes that the required external dependencies are also available on the machine of the FMI importing tool (e.g., typically if the FMU is also used on the machine to which it was exported).