Modelica Standard Library

The Modelica Standard Library (package Modelica) is a free, comprehensive library developed by the Modelica Association. It provides standardized model components and interfaces across multiple engineering domains, including:

• Mechanical: 1D and 3D modeling.
• Electrical: Analog, digital, and electrical machines.
• Magnetic & Thermal: Modeling of magnetic and thermal systems.
• Fluid: Fluid dynamics and flow components.
• Control Systems: Control logic and hierarchical state machines.
• Mathematical/Utility: Numerical functions, string handling, file I/O, and stream functions.

Each component in the library includes official documentation available at doc.modelica.org.

To use the Modelica Standard Library, you must have a Modelica simulation environment installed.

• Most commercial Modelica tools include the standard library by default.
• You can find a list of supported tools on the Modelica tools page.
• Note: Some demo versions of commercial simulation tools may have limitations that prevent simulating non-trivial examples from the library.

The Modelica/Resources/BuildProjects directory provides build projects intended to help tool vendors construct object libraries from the C source code located in ../C-Sources.

These projects can be used as a starting point to generate binary libraries (such as .lib, .dll, .a, or .so files) required for Modelica tool integration. Note that tool vendors are responsible for the actual compilation and inclusion of these binaries into their respective software tools.

When compiling libraries (.dll, .lib) or executables (.exe) on Windows that include gconstructor.h (specifically for ModelicaInternal.c or ModelicaStandardTables.c), apply these settings in the Release configuration of Visual Studio 2013, 2015, or 2017:

• Compiler: The option /Zc:inline (Remove unreferenced COMDAT) must not be set. Either omit the option or explicitly use /Zc:inline- to unset it.
• Linker: If /GL (Whole Program Optimization) and /LTCG (Link-time Code Generation) are enabled, you must set /OPT:NOREF (Keep unreferenced functions).

The ModelicaTest/Resources/Reference/ directory contains variable names for all test models. These names are used as comparison signals to verify model behavior during testing.

To implement a new test case, follow these requirements:

1. Directory Structure: The directory structure must mirror the library tree of the ModelicaTest package.
2. File Naming: Each directory must contain a file named exactly comparisonSignals.txt.
3. File Content: The comparisonSignals.txt file must list the variable names to be used as signals. The first line of the file must be the time signal.

time
variable_name_1
variable_name_2

When a Modelica model uses the library annotations ModelicaExternalC, ModelicaIO, or ModelicaStandardTables in an external function, the corresponding object library must be provided by the linker or dynamically linked to the simulation environment.

Backwards-compatibility (MSL v3.2.1): To support MSL v3.2.1 and later, tool vendors must ensure that the ModelicaStandardTables library automatically resolves its dependencies on ModelicaIO, ModelicaMatIO, and zlib. This is typically achieved by building shared object libraries (.dll, .so) and linking them in the following chain:

• ModelicaStandardTables $\rightarrow$ ModelicaIO $\rightarrow$ ModelicaMatIO $\rightarrow$ zlib.

Tool vendors must compile the *.c files in the Modelica/Resources/C-Sources/ directory into specific object libraries. The required libraries and their constituent files are:

• ModelicaExternalC (.lib, .dll, .a, or .so):
  • ModelicaFFT.c
  • ModelicaInternal.c
  • ModelicaRandom.c
  • ModelicaStrings.c
  • win32_dirent.c (required for Visual C++ on Windows)
• ModelicaIO (.lib, .dll, .a, or .so):
  • ModelicaIO.c
• ModelicaMatIO (.lib, .dll, .a, or .so):
  • ModelicaMatIO.c
  • snprintf.c
• ModelicaStandardTables (.lib, .dll, .a, or .so):
  • ModelicaStandardTables.c
  • ModelicaStandardTablesUsertab.c
• zlib (.lib, .dll, .a, or .so):
  • All files in zlib/*.c

The Modelica/Resources/Reference/ directory contains text files used for testing purposes. These files store variable names of example models that serve as comparison signals.

To implement a new set of comparison signals:

1. Follow the library tree structure of the Modelica package.
2. Name each file comparisonSignals.txt.
3. Ensure the first line of every file contains the time signal.

time
variable_name_1
variable_name_2

The Modelica/Resources/BuildProjects/VisualStudio2005/ directory contains Microsoft Visual Studio project files used to compile C source code into object libraries. These libraries are located in the Resources/C-Sources directory and are intended for use in environments like Dymola.

To ensure compatibility with Dymola, use the LIB Release configuration, which builds static libraries (*.lib) using the /MT (Multi-threaded) runtime flag.

zlib 1.3.1 is a general-purpose, thread-safe data compression library. It implements several data formats defined by IETF RFCs:

• zlib format: RFC 1950
• deflate format: RFC 1951
• gzip format: RFC 1952

For C API details, refer to zlib.h. Usage examples are available in test/example.c and test/minigazip.c.

zlib is available across multiple programming environments:

• Java: Use the java.util.zip package.
• Python: Available in Python 1.5+ via the zlib module.
• Perl: Use the IO-Compress interface.
• Tcl: Built into the Tcl language.
• C/C++: Core library provided in the source root.