About Simulation

A simulation is a single computation, which is based on the parameters that you define in the model.

The computation involves model translation and compilation, simulation run, and simulation data collection. You can start a simulation using the Simulate command from the Design section of the action bar. For more information, see Simulating a Model.

This page discusses:

See Also
About Parametric Simulation
Editing Parameters and Variables
User Interface Description

Simulation

A simulation:
  • Creates a Simulation object under the assessment template if simulated for the first time. It updates the object if it already exists.
  • Computes the internal variables that were not visible before the simulation and displays them under the Computed Variables node of the variable editor. You can use these variables for post-processing.
  • Generates a message about the simulation in the Message report panel.
    Tip: If the panel is not visible, click the message alert icon in the lower-right corner of the work area to restore the panel.
  • Updates the simulation status in the upper-right corner of the widget window and the icon of the Simulation object in the tree.
    Note: The simulation status is contextual to the selected model.

Simulation Task

A simulation task lets you perform complex calculation sequences. There are different types of simulation tasks depending on their capabilities. For example, a parametric simulation task simulates a model several times with different parametrization. For more information see, Simulating a Parametric Task.

A simulation task may have several steps of calculations. Each calculation step has some configurable inputs and outputs in the form of data and optionally some actions to display this data. For a parametric simulation, the task has one step. The task accepts a list of parameters and their variability as inputs. It produces output in the form of simulation results.

Notes:
  • A task with several steps can be replayed if the previous steps are calculated.
  • The task is stored into the database and is available as a template for the Analyst.

Simulation Status

Simulation updated
The simulation is considered updated if it is successfully executed and the model is not modified since the last simulation run.

An updated simulation can be distinguished using the following changes in the user interface:

  • The simulation status in the upper-right corner of the widget turns green and displays the Simulation up-to-date message.
  • The Simulation object in the tree displays the icon.
  • The diagram components whose parameters were modified before simulation, are no more highlighted with orange triangles.


Simulation not updated
The simulation is considered not updated if it failed during execution or if the corresponding Modelica model is modified since the last simulation run. Consequently, the simulation results do not correspond to the current revision of the model.

A simulation that is not updated can be distinguished using the following changes in the user interface:

  • The simulation status in the upper-right corner of the widget turns orange and displays the Simulation NOT up-to-date message.
  • The Simulation object in the tree displays the icon.
  • The diagram components whose parameters are modified, are highlighted using an orange triangle.