Release Notes

Introduction

Overview

In the course of the product support for SimulationX, the software receives ongoing updates and improvements. The basis for the continuous development of our software products are the requirements and suggestions from our customers in industry and education. These Release Notes document the changes between the versions of SimulationX and cover new features, enhancements and extensions of existing functionalities as well as bug fixes.

 

For any support query, please use the HelpDesk which is our primary point of contact: http://helpdesk.simulationx.com

Release Notes Structure

The Release Notes are given as a list and follow the manual's structure. The left side of the table contains a key which stems from processing. Please note the following:

Nxxxxx

New features in the program

Hxxxxx

Processed queries, requests addressed to the HelpDesk; the number here corresponds with the reference number at the HelpDesk

Bxxxxx

Bugs that were fixed. Changes (or new features) are described on the right-hand side.

Version 4.3.2 (May 2022) Hotfix

Solved Problems

B27454
H30752
During animation, objects in the 3D View are not displayed completely.
B27882
H30802
The Output Area may stop displaying messages until SimulationX is restarted.

Known Problems

Applies to all SimulationX versions: Due to a bug in the GCC compiler that comes with SimulationX, the program may freeze or crash during or after a simulation. Until a newer and fixed version of the GCC compiler becomes available, resort to one of the following workarounds:

  1. Use a supported Visual Studio compiler. It may require a valid license. For more information about the various Visual Studio products and their license conditions, go to Visual Studio: IDE and Code Editor for Software Developers and Teams
  2. Enable Code Splitting by setting the b.SplitCodeGen entry in the advanced solver settings of the preferences for transient simulations to true. For new models, this is the default setting. For models created with a previous version of SimulationX, check this setting before you run a simulation and save the model after making any changes.

Version 4.3.2 (April 2022) Hotfix

Solved Problems

B27299
H30740
CAD geometries from types are displayed only after the 3D View has been opened for a second time.
B27349
H30653
If there is no license available for the Hydraulics library, unstable behavior occurs during the drawing of valve icons.

Known Problems

Applies to all SimulationX versions: Due to a bug in the GCC compiler that comes with SimulationX, the program may freeze or crash during or after a simulation. Until a newer and fixed version of the GCC compiler becomes available, resort to one of the following workarounds:

  1. Use a supported Visual Studio compiler. It may require a valid license. For more information about the various Visual Studio products and their license conditions, go to Visual Studio: IDE and Code Editor for Software Developers and Teams
  2. Enable Code Splitting by setting the b.SplitCodeGen entry in the advanced solver settings of the preferences for transient simulations to true. For new models, this is the default setting. For models created with a previous version of SimulationX, check this setting before you run a simulation and save the model after making any changes.

Version 4.3.2 (March 2022)

News and Changes

N10001  The pipe elements (type Pipe) in the Hydraulics and Pneumatics libraries now have a new option to create user-defined lambda functions for laminar and turbulent regions. It also offers a new result variable for the pressure loss coefficient.
N10002  The library components of the Hydrogen Power library now also take gas humidity into account. The fuel cells now work not only with pure oxygen, but also with air.
N10003  The Weather element of the Driving Maneuvers library can now take 3D maps for density and wind speeds into account.
N10004  The Event-Controlled Sample-and-Hold Block element (type in SignalBlocks.Special.EventSH) has a new breakLoop option which allows you to break algebraic loops in the signal path continuously or when an event is triggered or both.
N10005  The Driver2 model and the Driver2ManGen model with integrated standard maneuvers in the Driving Maneuvers library have been revised. Among other things, the lateral deviation control has been revised so that maneuvers in global y direction and complete u-turns can also be driven in a controlled manner (closed loop). The anticipatory control (feedforward) can now take the relationship between the steering wheel angle and the steering angle of the wheels into account. The path's curvature, the gradient for oversteering or understeering and the anticipatory steering wheel angle are available as new result variables. These changes require adjusting the parameters for the lateral control.
N10006  The 3D visualization of MBS RigidLinks and spring elements has been improved.
N10007  For Boolean parameters in user-defined types with checkBox=true annotation, the name of the parameter is now shown in brackets.
N10008  By default, initial Jacobian matrices in blocks are now calculated numerically if the number of variables in a block exceeds 200. This can be changed in the simulation control settings for the symbolic analysis.
N10009  The name stem for models in the German GUI is now also "Model".
N10010  Functions that are used to detect discontinuities, as they change their algebraic sign in such a case, are now consistently referred to as zero-crossing functions in messages.
N10011  Saving and restoring solver settings in the program's options as the default for new models is no longer supported. Instead, a model template with the appropriate settings should be used as the basis for new models.
N10012  SimulationX now also supports Visual Studio 2022.

Solved Problems

B06053 The pipe element HeatTransfer.BasicElements.InternalFlow.Pipe causes random error messages when the connectors are not connected.
B12843 Array indices are missing, if tracing is used with compiled solvers.
B15780 The terminate("...") function is unable to process "\" in a string.
B22111 Compiling Synchronous models with BDF (compiled solver) causes errors if a different solver is selected in a partition.
B23481 The area parameter in the HeatTransfer.BasicElements.InternalFlow.GenericChannel element has no unit of measurement.
B24016 The animation of models with the SignalBlocks.Special.Ramp element does not work.
B24174 An incorrect default value for the deltaHeightSingle[n+1] parameter causes dimensional errors during simulation.
B25623 Values from a clock partition are not passed on to the result window until the next clock tick of this partition.
B25670 Packages may be loaded without a matching uses(Modelica(version="xxx") annotation, even though different versions of the Modelica Standard Library (MSL) are required.
B25711 Closing the TypeDesigner with Cancel after starting to create a new version via the Library Bar does not delete the newly created version.
B25841 Loading certain compilations of libraries causes the error message SignalBlocks.Sources.PeriodicSignal in: Unknown base class to occur.
B25961 InitialEquations in the ElectroMech.Machines.SM element are only valid if the initial values i_dq_0 in the parameter dialog are fixed.
B26046 With the scroll bar disabled, the text view cannot be moved, even though not everything is visible.
B26087 DLLs in the Windows System Cache are displayed as user DLLs in the Code Export Wizard.
B26158
H30428
BDF compiled causes memory usage to increase with each computation.
B26197
H30428
Certain FMUs with CVODE solver for Co-Simulation 2.0 generated by SimulationX yield incorrect results if the functions fmi2GetFMUstate and fmi2SetFMUstate are used.
B26213
H30425
External solvers (CVODE, solvers with constant step size) and code export may terminate the simulation depending on the minimum step size dtMin shortly before the end point tStop which is then not logged if tStop is an equidistant log point.
B26236
H30465
FMUs (FMI 2.0) for Model Exchange with no outputs, continuous states and event indicators are not simulated correctly.
B26305 The initial pressure distribution in the Hydraulics.Lines.PipeLP element is incorrect in certain models.
B26328 Scrolling in the output window does not work as expected if it holds more than 2 16 lines.
B26331 Duplicating an element with result variables enabled prevents result windows of the copied element from opening.
B26348 Incorrect algebraic signs for deflection, spring and damping force cause inconsistent behavior compared to independent suspension if curves are used (kindSpring=="Nonlinear").
B26369 If the the(y,x) operator receives an array as argument, errors occur during the C code compilation.
B26384 The toolbar for elements is not displayed on a deeper level of a connection.
B26398 It is not possible to set continuous state variables with fmi3SetReal in FMUs (FMI 2.0) for Model Exchange exported from SimulationX.
B26400
H30324
The "Keep Arrays Together" option may in rare cases cause incorrect simulation results during natural frequency analyses.
B26407
H30461
In rare cases, conditions with v>0 are removed, because the global symbolic analysis (GSA) makes incorrect assumptions about v.
B26413
H30518
Exporting FMU with initial values for multidimensional inputs may cause translation errors.
B26418 Switching from one element type to another deactivates the selected result variables.
B26439 The properties dialog of an element can disappear if a parameter's unit of measurement is changed within the selection menu (via the "+" symbol).
B26440 The results in the properties dialog of the Fin and Tube Heat Exchanger disappear if one of the result's unit of measurement is changed.
B26452
H30507
The SignalBlocks.Clocked.Hold element cannot process vectors automatically.
B26453
H30517
Re-declared records may cause creation errors in conjunctions with compiled solvers.
B26462 Changing a parameter in a model calculated with an external solver calls the constructors of external objects.
B26465 A new model can sometimes have the same name as a loaded model.
B26479 When loading a model, SimulationX may fail to execute the automated license request correctly.
B26484 Saving result window settings as the new default settings fails to refresh all open windows with the new settings.
B26494 Displaying a great number of tracing messages may freeze the graphical user interface.
B26498 Opening the backstage area takes a long time.
B26527
H30521
Links in the Help pointing to local files fail to open with the Firefox browser.
B26543 Right-clicking does not activate the selected view, which may cause commands in context menu to be applied to the wrong model.
B26629 A removed archiveDirectory() entry for a file path in a string parameter is restored after the model was saved and loaded again.
B26632 The Global Symbolic Analysis (GSA) may freeze in case libraries need to be reloaded.
B26652 Belts in 2D belt drives are not animated.
B26685 Opening the properties dialog of a fluid connection during the Global Symbolic Analysis (GSA) causes SimulationX to crash.
B26700 Generating the tracing code while an error message is generated causes errors if exceptions occurred during the generation.
B26702 Calling fmi2Reset in FMUs (FMI 2.0) for Model Exchange causes an invalid memory access.
B26707 Putting a type with expandable ports in a model renders it singular.
B26735 The TypeDesigner may crash if the dimension of records is changed.
B26738 The TypeDesigner removes dialog annotations from database links.
B26743 Exporting results as CSV uses the settings for the TXT format export.
B26811 The FluidDesigner (hydraulics) creates fluids with incorrect viscosities if Rapidly biodegradable fluid or User-defined fluid is used as the classification and ISO viscosity class according to DIN 51519 is selected for the viscosity approach.
B26827
H30608
On Linux, an executable model terminates on the second occurrence of a floating-point exception.
B26916 During code export with TDM-GCC, compiler options are written to the Makefile with a delay.
B27086 In vehicle models of the Driving Maneuvers library, the result variable Fcn[4] for the wheel's normal forces returns incorrect values.
B27087 If Visual Studio 2022 is installed, compiler detection in SimulationX may fail or crash.
B27106 Saving models with embedded types may render the model file unusable.
B27109
H30621
The storage type of a model from an external package changes from file to environment when a model is loaded with this component.
B27121
H30646
Connecting multiple sequences with different physical quantities to a database column causes SimulationX to crash.
B27126
H30627
If a simulated model is saved and opened again, its animation fails with an error message.
B27135
H30655
The locally installed (offline) Help does not work with Chromium-based browsers.
B27254
H30692
Under certain circumstances, data of characteristic curves may not be saved.

Known Problems

Applies to all SimulationX versions: Due to a bug in the GCC compiler that comes with SimulationX, the program may freeze or crash during or after a simulation. Until a newer and fixed version of the GCC compiler becomes available, resort to one of the following workarounds:

  1. Use a supported Visual Studio compiler. It may require a valid license. For more information about the various Visual Studio products and their license conditions, go to Visual Studio: IDE and Code Editor for Software Developers and Teams
  2. Enable Code Splitting by setting the b.SplitCodeGen entry in the advanced solver settings of the preferences for transient simulations to true. For new models, this is the default setting. For models created with a previous version of SimulationX, check this setting before you run a simulation and save the model after making any changes.

Version 4.3.1 (February 2022) Hotfix

Solved Problems

B26381
H30278
In rare cases, compiled solvers may cause array-related compilation errors in ConstConditionsChanged.
B26422 Adding connectors to compound elements deletes existing connection lines.
B26635
H30545
Selecting result variables in the I/O analysis is not possible.

Known Problems

Applies to all SimulationX versions: Due to a bug in the GCC compiler that comes with SimulationX, the program may freeze or crash during or after a simulation. Until a newer and fixed version of the GCC compiler becomes available, resort to one of the following workarounds:

  1. Use a supported Visual Studio compiler. It may require a valid license. For more information about the various Visual Studio products and their license conditions, go to Visual Studio: IDE and Code Editor for Software Developers and Teams
  2. Enable Code Splitting by setting the b.SplitCodeGen entry in the advanced solver settings of the preferences for transient simulations to true. For new models, this is the default setting. For models created with a previous version of SimulationX, check this setting before you run a simulation and save the model after making any changes.

Version 4.3.1 (December 2021)

News and Changes

Software

GUI
N10001  The Libraries page in the general settings has been completely overhauled. Only the top-level libraries are now displayed. For multiple versions of a library in the Modelica search path, you can now switch between them based on the version or the file path. Clicking OK or Apply now also performs a plausibility check verifying whether the versions of the selected libraries match the versions referenced in other libraries and if there are valid licenses for all of them. On top of that, the overall performance for displaying the library list has also been improved.
N10002  SimulationX now comes with the latest version of the Modelica Standard Library (MSL). It includes both version 3.2.2 and 4.0. By default, the current version 4.0 is loaded automatically. This behavior can be changed in the program options.
N10003  SimulationX can now manage multiple versions of a library. Since only one version of a library can be loaded at a time, it is now possible to embed another version when a model is being loaded which is only visible to this model. Version conflicts shown in the output area can be resolved with Modelica conversion scripts which can be used to switch models to a newer library version that is available in the model. The related files must be loaded via FileOpen. A dialog will guide you through the conversion process. If version conflicts cannot be resolved through conversion, you should check the Modelica version information in your models and libraries, especially the Modelica annotations version and uses. When models or top-level packages are saved, SimulationX includes information about the used libraries and versions as uses annotations. Models and libraries saved with earlier versions of SimulationX usually do not have any Modelica version information. Therefore, references to the Modelica Standard Library are assumed to refer to MSL version 3.2.2 shipped with SimulationX up to version 4.2.4. The same goes for the Electric Energy Storages and Green City libraries.
N10004  The SimulationX add-ins management under FileOptionsMaintenance and Add-Ins has been completely revamped. The following add-ins are currently available as downloads in the myESI customer portal:
  • ROM Import (imports reduced-order models (PGD) from ESI VPS)
  • Simulation Service (runs simulations in other instances of SimulationX)
N10005  The new PGD Importer addin is a tool for SimulationX that allows you to integrate parametric solutions from the results of a three-dimensional FEM or CFD simulation into your SimulationX model. The addin makes use of ESI's proprietary PGD (Proper Generalized Decomposition) technology with the accompanying file format EPGD2. Importing PGDs as SimulationX blocks enriches your system model with the results of detailed 3D simulations of flexible bodies or complex flow structures.
N10006  With the new Simulation Service addin, you can plan and run multiple simulations in the background.
N10007  Usage data and crash reports can now be sent to ESI servers to allow ESI developers to identify priorities in the work with the software. This data is also useful for debugging purposes and general improvements. The usage data is always part of the automatic crash reports that SimulationX can generate if the program was not closed correctly. The privacy settings can be adjusted in the program's general options.
N10008  A background image can now be displayed in the panels of a result window. For better readability or for a direct comparison with existing data, it may be helpful to use a particular image as background directly under the result curve. Backgrounds can be specified for each panel individually via the property bar or the context menu.
N10009  The Alt key navigation has been added to all ribbon commands to improve navigation without a mouse and general usability.
N10010  Pointers values of external objects are now displayed in the Model Explorer also for compiled solver methods.
N10011  The Code Export Wizard now displays a warning message when tStop is infinite.
Performance
N10001  The license management initialization has been improved. SimulationX now starts faster, especially when a network license server is used. The module selection dialog's performance has also been improved. A progress bar has been added, and modules without a license are now included.
N10002  Saving models is now faster. This also applies to copying partial models and to other functions creating copies of elements and partial models for undo operations. The format for some non-Modelica-compliant information has been changed, which means that models saved with version 4.3 will not be loaded completely in earlier versions of SimulationX. This affects:
  • models with MBS or animation bodies,
  • models with database interfaces and
  • computed models.
N10003  Updating a model after a fluid was changed is now up to 4 times faster.
N10004  OpenGL and DirectX 9 are no longer supported and were replaced with OpenGL2 and DirectX 11. The OpenGL mesa driver can now be used if no 3D hardware is available.
Solvers
N10001  The output of changed discrete variables has been improved. Until now, only changes in pre values of discrete variables have been reported. The variable name is now marked with pre_, and the change of discrete variables is also shown in the inner event iteration for internal solvers. The output for sign changes of zero-crossing functions with external solvers and code export has also been improved. It is now linked to the tracing setting for resetting the time when the sign of a zero-crossing function changes after a valid step, similar to the internal solvers. If the option Sign change of zero-crossing functions is enabled, the output now also includes a message with the actual sign change of the zero-crossing functions in the same way as the internal solvers. In both cases, the number of the zero-crossing function and the calculation of its value are also shown.
N10002  For the Fixed-Step solver, hysteresis is now off by default for zero functions.
N10003  The splitting functionality for generated code has been improved and extended. For the compiled solvers, you can now change the number of statements per split function when code splitting is enabled by selecting the iSplitStatementsPerFunction parameter under PropertiesMoreMore Parameters.
N10004  The steady-state simulation now takes assert(...) statements into account. It checks pre-conditions specified by the user or through library implementation, and the simulation is aborted if these conditions are not met.
Modules
N10001  The sales modules MBS Actuators, System Reliability Aanalysis (4 cores) and Non-Newtonian Fluids have been discontinued.
N10002  The sales modules Ventilation and Air Treatment and Power Generation have been moved to HVAC and Power Generation (Lite) and the module configuration SimulationX for HVAC and Power respectively. The corresponding libraries have been distributed across the HVAC and Power Generation (Basic) (formerly Heating and Cooling) and Thermal-Fluid libraries. Existing models work as usual. The new structure is applied automatically when the model is loaded.
Other Features
N10001  The file-based CAD import has been updated.
N10002  The local help is no longer part of the installation setup, but can be downloaded from the myESI customer center.
N10003  The free Viewer Edition has been discontinued.
N10004  New example models have a documentation view that allows for a better visualization of texts, images and equations.
N10005  The example collection includes a new model for subsea hydraulics applications.

Libraries

Driving Maneuvers
N10006  The Driving Maneuvers library has been revamped completely. The new sub-library Generic Components includes various wheel models with integrated tire-road contact and flow elements. The latter can be used to generate a lift effect or a downforce (rear spoiler). All passenger car models (Automotive Vehicle Configurations) have been harmonized to make parameterizing them and switching between model types easier. The curve-based vehicle components have been modified so that they can be used independently of the vehicle models. The Air Drag model has also been revised and enhanced. For aerospace applications, the new Aerospace Vehicle Configurations offer a conventional aircraft and a so-called vertical take-off and landing vehicle (VTOL).
N10007  The new sub-libraries for FTire and Simcenter Tire include road, tire contact and wheel elements. The road elements can be used to describe the ground for all tire contact elements used in the namespace. The tire contact elements describe the contact between tire and ground using the cosin Tire Interface (CTI) and Siemens MF-Tyre/MF-Swift API interfaces to the FTire and Simcenter Tire software packages, respectively. The wheel models add various visualization capabilities and inertia properties to the tire contact elements.
Electrical and Electronics
N10008  The two new elements Linear Electromotive Force and Rotational Electromotive Force are converters between electrical and mechanical energy.
Electrical Energy Storages
N10009  The library has been updated by the Austrian Institute of Technology. Version 4.0.1 now supports version 4.0 of the Modelica Standard Library (MSL) and includes various new features for the aging models. For more details, please refer to the library's documentation (User's GuideChangeLog).
Electro-Mechanics
N10010  It is now possible to import JMAG-RT Generic Models, and all JMAG-RT motors now support user-defined output parameters.
N10011  The DC motor, synchronous motor, induction motor, and doubly-fed induction motor can now take torque imbalance into account.
Green City
N10012  The library has been updated to version 4.0.0 of the Modelica Standard Library (MSL).
Hydrogen Power
N10013  The new Hydrogen Power library as part of the HVAC and Power Generation (Basic) module includes the Electrolyzer and Fuel Cell elements for the simulation of hydrogen technologies.
Mechanics
N10014  The new Surface Contacts library (type Mechanics.MechanicsMBS.Contacts) can be used to define uneven surfaces and identify contacts with them. The point-shaped contact object Point can be connected to MBS components via kinetic MBS connectors. When a contact with the subsurface has been detected, it calculates recoil and friction forces.
Pre- and Post-Processing
N10015  Python scripts can now be used with multiple SimulationX instances running simultaneously.
N10016  The GenerateMap element (type General.PrePostProcessing.BatchProcessing.GenerateMap3D) now also allows you to create 3D maps based on a variant study.
Ship Energy Systems
N10017  The input data in the tables for ambient conditions, engine profiles and electrical power consumption can now be customized in more detail.
N10018  The new battery unit (type ShipEnergySystems.EES.BatteryUnit) and the accompanying battery management system can be used for low and peak loads.
Signal Blocks
N10019  The new source Periodic Signal adds further options to the harmonic synthesis for modeling periodic signals. Characteristic curves (angle) and Fourier coefficients can be used for the parameterization.
Thermal-Fluid
N10020  The Dynamic Transformer and Volumetric Transformer element types have been moved to the new Work and Power Machines subfolder. The Reciprocating Compressor and Steam Turbine element types have been moved from the IndustrialUtilities.WPMachines library to the new Work and Power Machines subfolder. The State Diagram and State Sensor element types have been moved from the IndustrialUtilities.Diagrams.StateDiagrams library to the new Diagrams subfolder.

Solved Problems

Software

B10407 Text is not displayed in a text field if the content is edited in another Diagram View.
B17235 It is not possible to freeze result curves in the result window that include transformations with operands which themselves include frozen result curves.
B17754 The current simulation time is not correctly displayed in the solver statistics for CVODE and Fixed-Step if tStart is not 0.
B20021 The delay operator with constant delay time does not work correctly in steady-state simulations.
B22966 Executable models with Fixed-Step solvers are not closed correctly in case of a successful simulation.
B23096 The reference results of startBackward and startForward from the Modelica Standard Library (MSL) may cause invalid tests.
B23147 Modelica asserts with AssertionLevel.warning are not displayed correctly in CVODE.
B23469 Specifying a variable as the initial value in the dead time element may cause incorrect results.
B23563
H28966
A duplicate function in the model returns an incorrect dimension.
B23902 trace(), message() or warning() within a model may result in incorrect behavior during compiled simulation or code export.
B23916 Changes to local types are not propagated to instances of this type via the COM interface.
B23917 For certain models, the Fixed-Step solver fails if the step size is reduced after a failed computation even if the reduced step size succeeded after a symbolic analysis.
B23967 Some models work with certain solvers only with an alternative choice of iteration variables (Simulation OptionsSymbolic Analysis) and others only without them. If the model does not run, this setting can be changed, which may change the used system of equations.
B24072 In the module selection, an incorrect expiration date is displayed for modules that are currently unavailable.
B24097 Computed and saved models with CVODE cannot be animated when they are opened again.
B24208
H29143
The fmi2GetFMUstate function does not work.
B24280 Result windows of a model which was saved with a standard resolution are very small and may be even incomplete when a 4K resolution is used.
B24306 SimulationX crashes when it attempts to unload/reload a package in the library tree while a child class is being processed or instances of the class are used in a simulation or in an active code export.
B24352
H29151
The BDF compiler computes differently than BDF.
B24354 Loading models with compiled simulation triggers the error message "Could not move generated DLL."
B24607 Modelica blocks derived from states are not represented as states and you cannot add a transition.
B24627 The bar chart in the results window is incorrect in many cases.
B24639 Changes to the dtMin and Tol simulation settings trigger a new symbolic analysis (GSA).
B24658 Moving states associated with initial state changes the distance between both states.
B24703 The output shows an error message and a success message at the same time.
B24707 Result variables for the temperature in conjunction with a y(x) representation cause the unit of the y-axis in the result window to be displayed incorrectly.
B24711 If multi-dimensional model parameters are selected, compilation errors may occur during the generation of S-function.
B24716 If result windows for vector result variables are opened through drag & drop from the Model Explorer and the components are then spread across several panels, the moved curves are added back in to the original panel.
B24721 If two open models have the same name, one model may overwrite the model DLL of the other during the compiled simulation.
B24724 Compiled solvers may cause incorrect results if parameter dimensions are set through files.
B24730 Defining the dimension calculation through an external modification may cause an error.
B24752 During a compiled simulation with BDF, the generated code for Jacobian matrices may be reduced in size.
B24776
H29246
Using the Zoom button in the backstage area causes SimulationX to crash if the list of recent files is empty.
B25069
H29246
Enumeration types of built-in elements appear in the library tree even though they should not.
B25084 Diagrams with certain axis settings in the Diagram View can cause SimulationX to crash.
B25085 Saving computed models with synchronous (clocked) elements and animation data produces syntactically incorrect models.
B25093
H29140
Steady-state simulation results may be incorrect if two rotational inertias are connected through a constraint. This is especially true if the symbolic analysis selects the angle of one inertia and the rotational speed of the other inertia as state variables.
B25138 Saving embedded types causes unnecessary import statements to be written into the model which may prevent the model from loading without the source libraries.
B25326 Holding certain array equations together with Cat expressions causes a dimension error during the symbolic analysis (GSA).
B25375 Models with FMUs and a homotopy operator fail during the initialization with BDF.
B25389
H30289
Deleting a connection may cause translation errors in the generated code when a compiled solver is used.
B25390 An incorrect error message is shown about a cyclic reference in a parameter.
B25392 Resolving external references (when a model is saved with embedded types) may cause SimulationX to crash.
B25394 The floor, ceil and integer operators are not processed correctly in steady-state simulations.
B25418 Selecting individual elements may fail if several views of a model representing a local type, for example, are open.
B25420 After a type was deleted in the Diagram View, the remaining elements are no longer shown.
B25444
H29018
Result windows with very large display ranges and frozen result curves can cause SimulationX to crash when the simulation is restarted.
B25538
H30285
Parameters in references of multiple active models become absolute values if the model name is included in the type's name during the component's declaration.
B25574
H30315
Copying a model structure through drag & drop places connection points incorrectly.
B25600 The conversion of the unit for the (thread) pitch is based on 1 instead of 2*Pi.
B25632 Functions with records as inputs cannot be differentiated even if the corresponding record is constant.
B25647
H30334
In simulations with exported code, model parameters are not included correctly in the initial equations.
B25649 Switching from a symbolic to a numeric Jacobian matrix requires a new symbolic analysis (GSA) with BDFCompiled.
B25654
H30340
After Windows update KB5006729, some lines in the Diagram View and in the result windows are displayed incorrectly.
B25662
H30342
Exceeding clock ticks with MEBDF with clocks always resets the current time to the last valid step before the clock tick with the next time step starting from there causing an infinite simulation.
B25671
H30312
Saving a model in a Modelica-compliant way causes CVODE and BDFcompiled to include the DLL in the file.
B25673 BDFcompiled cannot run with homotopy.
B25717
H28448
In UserInit files, indexing of array components starts with 0.
B25758 Saving a model with embedded types may cause SimulationX to crash if one of the embedded types is being edited in another open window.
B25774 The arrows that are used to change the index in the dialog for connecting multi-dimensional Modelica connectors are shown at the wrong position.
B25776 S-functions from SimulationX cannot be initialized in Simulink.
B25777 Random compilation errors occur during code generation if the model's Text View is open.
B25779
H30379
Boolean parameters in records (shown as checkboxes) cannot be changed in the properties dialog.
B25795
H30321
If an unresolved reference is ignored when a model is opened, the model remains locked and cannot be removed or unloaded in the library bar.
B25803
H30386
The automatic generation of reset points does not work.
B25825 Functions with trivial return statements cannot be differentiated symbolically.
B25835 SimulationX crashes if sequences are linked to the database via Master/Detail Columns or when the unit is changed.
B25854
H28318
Multiple connections at an expandable port cause an error during the symbolic analysis (GSA).
B25878 In models that use synchronous elements with CVODE, ticks are computed relative to 0 even if the start time is greater than 0.
B25890
H30406
Nested if statements whose outer if conditions contain a NoEvent expression return an error for the inner conditions, even though the outer condition is constant.
B25917 Clock ticks in models that use synchronous elements with BDF are calculated relative to 0 even if the start time is greater than 0.
B25944 The Model Explorer's parameter page displays an error when a simple parameter is changed after a component has been re-declared via the parameter page.
B25988 Changing the visibility of connectors through connection settings may not take effect until the model is saved and reloaded.
B25991 Boolean variables are not calculated correctly during a simulation under certain conditions.
B26001 Logarithmic axes in the result window have no unit of measurement if the DIN 461 option is used.
B26002 Tracing with CVODE does not work if code splitting is enabled.
B26041
H30407
Variables in differentiated algorithms are not initialized correctly under certain conditions.
B26043 Array parameters with evaluate=false may be evaluated incorrectly.
B26123 Simulating arrays of Modelica visualizers may cause SimulationX to crash.
B26140 The E-Learning Theory 4 shows an incorrect result when absTol is referenced in the fourth query.
B26145 S-function compilation with external functions is faulty.

Libraries

B23004
H28790
USign the CVODE solver may cause numerical problems with the hydraulic elements Plane Gap (type Hydraulics.Basics.PlaneGap) and Ring Gap (type Hydraulics.Basics.RingGap) if the inlet pressure loss is taken into account.
B23450
H30276
Convergence issues may occur in the hydraulic Fluid Designer if the specific heat capacity cp is parameterized with a table.
B25116 Models with hydraulic connections run slowly.
B25387 Settings for the 3D geometry of belt elements from the Power Transmission (MBS) library are only displayed after a simulation.
B25612
H30323
Models with elements from the System Reliability Analysis library trigger the warning Obsolete.VariableInStartAttribute.
B25679 Changing alphaURef for a hydraulic connection always triggers a new symbolic analysis (GSA).
B25770 The opening pressure with continuous opening behavior in the pneumatic check valve depends on the pressure of the maximum opening with two points.
B25881 The calculation of the contact force for Mechanics.MechanicsMBS.Contacts.CADParabolicCurve causes a division by 0 for some CAD geometries.
B26121 The parameters pn, Tn and Rn in the desiccant dryer and water drain elements of the HVAC and Power Generation library are shown as result variables.

Useful Tips

System Requirements

For the installation and execution of SimulationX you need Windows 8 (64 bit) or later.

Some features of SimulationX need a C/C++ compiler. It is recommended to install the Microsoft Visual Studio 2015. About the conditions for use of the free Express editions or Community editions of Visual Studio inform you at www.visualstudio.com

Support of the Modeling Language Modelica

SimulationX 4.3 supports the modeling language Modelica in accordance with the Modelica Language Specification Version 3.4 with certain exceptions. The following features are currently not supported (the statements in brackets refer to the corresponding section in the Modelica Language Specification 3.4):
  • Annotations for user input (section 17.5.7)
    • OnMouseDownSetBoolean
    • OnMouseUpSetBoolean
    • OnMouseMoveXSetReal
    • OnMouseMoveYSetReal
    • OnMouseDownEditReal
    • OnMouseDownEditInteger
    • OnMouseDownEditString

Support of the Modelica Standard Library

SimulationX 4.3 includes version 4.0 of the Modelica Standard Library.

Performance

There are several ways to improve the performance of SimulationX:

  • Animating the Diagram View during simulations is especially demanding for older computers with only one CPU core. Disable this feature if you do not need it for real-time displays like bars, tachometers or Modelica graphics (Extras/Options/GeneralAnimation).
  • Providing trace information requires a great deal of computing resources even if the output window is minimized. Enable only those options under Simulation/Transient Settings/Tracing that you really need. Use the model parameter traceOn (tracing enabled) to limit the output to the relevant range (e.g.traceOn == time>0.6).

Using External Solvers for Simulations

  • Before computation, C code generation of the model and subsequent automated compilation is performed. Thus, the restrictions described above regarding supported model features apply. In order to use external solvers, a Microsoft Compiler.
  • It is recommended to install the Microsoft Visual Studio 2015.
  • Only certain tracing functions are supported.
  • Currently, not every type of analysis is supported for this solver. This affects:
    • Equilibrium computations
    • Linear system analysis (frequency response, pole-zero plot, export of system matrices)
  • Please employ the BDF or MEBDF solver for these analyses.
  • Reset points are not taken into account.
  • Initializing the model to a specific state is not possible.

Code Export

  • If external functions or objects are used in the model, the exported code has to be updated. During the export, a warning is displayed for these cases.
  • Exported C code of thermal-fluid models containing NIST fluids runs exclusively on Windows. The fluid properties are computed in external modules which are only available as binary files for Windows.

Rigid Mechanical End Stops and other Model Features

Code export of models containing specific features is currently not supported. This predominantly affects systems of equations whose structure changes considerably during simulation. This applies especially to rigid mechanical end stops, ideal electrical diodes, and models featuring unipolar stepping motors. If the model contains a rigid mechanical end stop or an ideal electrical diode (Electricity.Analog.Ideal.IdealDiode), a corresponding error message is displayed during code export.

A number of model objects can be parameterized to internally use rigid mechanical end stops:

  • The end stop model of the Mechanics library: Mechanics.Translation.EndStop, Mechanics.Rotation.EndStop
  • Basic mechanical elements which can be switched to rigid with backlash: Mechanics.Translation.SpringDamper, Mechanics.Rotation.SpringDamper
  • Joint models included in the MBS Mechanics library
  • Couplings, clutches, actuating elements, and transmissions included in the Power Transmission library
  • Hydraulic and pneumatic cylinder models

For the code export to succeed, it is necessary to switch to the option “Elastic End Stop”. A spring damper element is inserted in this case; Thus, it is necessary to make sure during parameterization to provide a sufficiently high damping.

Is the end stop not applied between two masses or inertias but against absolute, the end stop models Mechanics.Translation.AbsEndStop or Mechanics.Rotation.AbsEndStop, respectively, can be set to “rigid”. The code export supports these objects.

Periodic Steady State Simulation

Periodic steady state simulations with dynamic state selection may cause wrong results or convergence errors. Currently, the index reduction forces dynamic state selection for certain models, such as multi-body systems with general joints.

A warning is generated for those models. If the variables which are appropriate to describe the motion throughout the whole simulation are known in advance the stateSelect attribute of those variables can be set to "always". This can completely avoid dynamic state selection and the connected restrictions.

Alternatively the index reduction can be switched off by checking the box "No index reduction" on the page "Symbolic Analysis" of the simulation settings dialog for the periodic steady state simulation. If the model contains nonlinear hidden constraints such as a crank drive with rigid shaft or a transmission gear one of the nonlinear methods should be selected for the periodic steady state simulation. The nonlinear periodic steady state simulation computes all result quantities except the excitation results correctly without index reduction.

Choices Annotations in the typeDesigner

Choices annotations generated with the TypeDesigner do not contain any modifications. The modifications can be subsequently defined in the Modelica source code.

 

Choices without modifications can be defined by the typeDesigner:

replaceable typeBase model1 annotation(

choices(choice(redeclare replaceable typeA)));

end Container;

Choices with modifications can only defined in the Modelica view:

replaceable typeBase model1 annotation(

choices(choice(redeclare replaceable typeA(p1=10))));

end Container;