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2021.2 Release (version 1.2.6)🔗

Release 2021.2 (version 1.2.6)
General availability: Desktop 2021-JUN-15

Modelon is proud to release Modelon Impact 2021.2, delivering significant improvements and critical features. Launched in July 2020, Modelon Impact has set out to disrupt the way organizations engineer complex systems, keeping the barrier to modeling and simulation software as low as possible

Selected Highlights🔗



Build: Model Builder🔗

Model Code View🔗

There has been a significant improvement in the Modelica code editor making it easier and more efficient for experienced Modelica developers to create models programmatically.

Improved Modelica code editor

  • Improved source-code formatting
    • Duplicating a model now preserves formatting
  • Quickly navigate to a class
    • Open class by Ctrl + click
    • Use arrows to navigate back and forth classes
  • Improved readability
    • Theme selection – use a dark or light theme
    • Code folding – annotations are folded
    • Bracket matching - see where the code block start and end
    • Comment code – use Ctrl-B to comment/uncomment code
    • Word wrap – long lines are wrapped into multiple lines

Model Debug🔗

UI support for working with libraries and models with syntax errors

Models with syntax errors

Support for import and load of libraries and models with syntax errors.

  • Import or load a library - Syntax errors show up as red dots in the package browser. Light red dots indicate a syntax error in a model inside a package
  • Resolve issue - Manually resolve issues in the code editor. Editor help indicates where the issue is.

Note, only libraries stored in a folder structure with syntax errors can be imported.

Local equation balance checker

Local equation balance checker

Quickly verify that an equation system is locally balanced. This can increase productivity as a common error mode where equations & variables don’t match up can be detected early.

Other improvements

  • Improved compiler error messages for failed size evaluations
  • Improved diagnostics for encrypted models – easier to debug models including encrypted components
  • View the result of cancelled simulations

Improved Python scripting support in Optimica Compiler Toolkit

  • Model statistics in json-format
    • Set compiler option “generate_json_statistics”
  • Dynamic diagnostics Python package - "oct.diagnostics.DynamicDiagnostics"
    • Find which state(s) limit the ODE solver step size
    • Get the step lengths
    • Get the clock time of each step
    • Get the information on solver settings
    • List the time of events

Model Diagram View🔗

  • Improved support for redeclared components
  • Quickly inspect a component - Major loading time speed-up when inspecting a component, i.e. when navigating to a sub-system

Workspace browser: Library browser filter🔗

Library browser filter

Quickly find a model or file using a library browser filter.

  • Filter as you type with instant feedback
  • Filter by model, package or file name

Analyze: Solver🔗

Custom functions🔗

  • Custom function improvements – option to specify if a pre-compiled FMU is not required

Dynamic simulation🔗

  • Simulation speed-up – reduced overhead when executing from UI

Modelica compiler🔗

  • Improved symbolic manipulation – can in special cases reduce the size of equation systems which improves simulation performance
  • Support for Modelica inverse annotation - can improve simulation speed and robustness.
  • Support for Modelica annotation HideResult

FMU Co-simulation Import🔗

FMU Co-simulation Import

It is now possible to import a co-simulation FMU1 and connect and simulate it with Modelica models. A common use case is to import a controller develop in a 3rd party tool and connect it with a system model.


Licensed FMUs that have dependencies (like external license server) to third-party software/binaries that are distributed outside the Modelica library are not currently supported.

  • FMU-import tool that automatically imports an FMU and generates a Modelica wrapper model

1 Support for CS-FMUs generated on the same Operating System that Modelon Impact runs on (Windows on Desktop & CentOS 7 at Modelon managed.)

FMU Export🔗

  • New solver for CS FMU export - Runge-Kutta (2nd order).

MultiRun - Parameter sweeps with automatic parallelization of compilations🔗

Parameter sweep

Parameter sweeps now include user interface support for experiment set up that require multiple compilations. This improves the productivity as compilations are automatic parallelized.

  • Experiment support for “structural parameters” using range() and choices() operators
  • Automatic scheduling and parallelization of compilations


  • Improved optimization toolchain – support for more Modelica constructs in the Casadi-toolchain
    • Support of external functions, functions with unknown sizes, nested functions with unknown sizes, enumerations, better handling of if-statements
    • Increased the performance of CasADi transfer by around 60% for large models

Analyze: Visualization Tools🔗

3D-animation - Official support🔗


3D animation is now an official feature after being experimental since the 2021.0 release.

New functionality and improvements

  1. Out-of-the-box-support – no need to enable any settings
  2. Improved selection of objects – incl hiding objects to allow selection of objects inside
  3. View 3D animation only show up if animation is available
  4. Export 3D animation as GLB format - GLB is a widely supported binary 3D format that can be embedded into presentations (e.g. PowerPoint)
  5. A lot of quality improvements!

Display units🔗

  • Unit settings support in experiment setup – easier to set up experiments on a larger time scale


Plotting improvements:

Customize colors

  • Select a trajectory or result point and modify the colors using a plot UI
  • Color settings can be saved to views
  • Multi-color mode for parameter sweeps
    • Click on Edit “Line color” and choose the multi-color icon to enable it

Units on the Y-axis

  • See the unit on the Y-axis

Platform information🔗

Execution environment🔗

This release include following execution environment.

Execution environments v2021.2
Optimica Compiler Toolkit v1.28
   Modelica compliance v3.4 of Modelica Language specification1
   FMU compliance v2 (default) and v1
Operating system Windows
Python environment v3.7
C compiler GCC v5.1

1 See Optimica Compiler Toolkit User's guide for further information about Modelica compliance and limitations.


This release includes following library versions for Modelon Impact Desktop.

Library v2021.2
AircraftDynamics 1.5
Electrification 1.6
EngineDynamics 2.7
EnvironmentalControl 3.11
FuelCell 1.13
FuelSystem 5.0
HeatExchanger 2.7
Hydraulics 4.15
HydroPower 2.13
JetPropulsion 2.2
LiquidCooling 2.7
Modelon 3.7
Pneumatics 2.11
ThermalPower 1.22
VaporCycle 2.7
VehicleDynamics 3.7

And a lot of quality improvements - Enjoy!