Eagle eyed users will immediately notice that this year’s second release of Dymola breaks with the usual naming tradition; gone is the FD01 designation, in is the “x” nomenclature, but that’s not the only thing to change. The user GUI has undergone a complete overhaul, modernised to render a more streamlined modelling and simulation experience. Beyond this, it is worth noting that this will be the last Dymola version officially supporting Windows 7 users. Here’s some Dymola 2020x highlights.
All new GUI
Previously, the GUI (graphical user interface) was centred around the duality of separate modelling and simulation windows; all modelling functions were designed to occur in the modelling window, all simulation activities in the simulation window. As modelling and simulation tasks are not mutually exclusive, it was felt that this hindered the usability of Dymola as a tool. Now, 5 ribbon tabs group operations according to task; Graphics (diagram layer of models), Documentation, Text, Simulation and Tools (general Dymola options).
Each ribbon tab contains tools specific for its designation. One upshot of this is that there is now room for extra tools within each ribbon, with some highlights introduced below. Individual model tabs, previously under the single ribbon in the modelling window, have now migrated down to the bottom right hand corner. With such a comprehensive reorganisation of the GUI layout, many existing functions have been moved to a new location.
Simplified pedantic checking
With more room in the ribbon found by the GUI reorganisation, checking models in Modelica pedantic mode is now easier. Previously, an advanced flag was required to be set from the Simulation window. This has been replaced by a new option on the existing, normal check button found in the Text tab:
View flat Modelica within Dymola
Advanced users will be used to viewing the flattened Modelica code, as created through using Dymola. Previously, this entailed finding the correct file deposited by Dymola in the working directory; not anymore. As one might expect, the Text tab features previous text views (normal and mathematical notation), appended now with the option of viewing the flat Modelica code for each model. A useful feature, it’s now much easier to interrogate the flat Modelica for each individual model, rather than having to compile a larger model.
Potential Modelica name conflict warning
Some operating systems, such as Windows, do not differentiate between upper and lowercase names for files; Modelica, as we know, is case sensitive and supports case sensitive file naming. When mapping files in operating systems like Windows, this can cause issues. Dymola 2020x features a warning if models are given similar names, regardless of case, within the same scope. This is most applicable when models are given the same name (case independent) in the same package.
New Simulation Advanced flags
Five new advanced flags have been defined within Dymola; 3 surrounding simulation step size, 2 regarding events:
Advanced.Simulation.StepSizeMin: Define minimum step size for simulations
Advanced.Simulation.StepSizeMax: Define maximum step size for simulations
Advanced.Simulation.StepSizeStart: Define starting step size for simulations
Advanced.Simulation.EventEpsilon: Define time resolution for events
Advanced.Simulation.MaxEventIterations: Define maximum number of event iterations
As these flags define and affect the function of the solver during time integration, care should be used when deploying them. For instance, if the minimum step size is too large, the model will fail; similarly, if the number of event iterations is constrained to a value below the required iterations, then a model will fail as convergence will not be achieved.
Improved model warning
When creating models, the Check Model function of Dymola is vital to spot modelling errors and mistakes. In Dymola 2020x, this has been refined to further assist the user. A much clearer error message is shown, then the Evaluate = false annotation causes Dymola to be unable to translate a model.
All together, Dymola 2020x represents the most comprehensive overhaul of the user experience in recent release history. Change, as always, requires some getting used to. Once familiar with the new layout, Dymola 2020x feels slicker, streamlined and more intuitive than ever before. For further information regarding Dymola 2020x, please see the version specific release notes.
Written by: Theodor Ensbury – Project Engineer