VTB Architecture

    The Virtual Test Bed provides many flexible, robust, and extensible means for integrating models into a unified simulation environment. The VTB models can be created in many different ways. For example, the entities can be exported from other simulation tools, such as Matlab, Simulink, Spice, ACSL, and even Fortran, using the VTB wrapper entities. The great advantage of this approach is that the model entity is used in the VTB in the way it was originally designed to be used in its native tool, i.e. there are no translations involved and the modeler can be absolutely sure that the entity behaves in the VTB precisely the same way as it does in its native language. Another way of creating the VTB entities is through translations. For example, a model originally created in Modelica, VHDL-AMS, ACSL, etc. can be brought to the VTB environment through Paragon software. Paragon software first invokes the Multi-Translator, which brings the model into the universal XML based specification. After that, Paragon brings the XML specification of the model into the form required by the User-Defined Device (UDD) software, which is part of the VTB development kit. The UDD creates the C++ source code for the model, which then can be compiled and used as a native VTB entity. Besides the ways described, wrappers or translation provide many other different ways of creating the VTB models .

    The major modules of the VTB software are:
* The Schematic Editor, which is responsible for visual representation of the system model, provides tools for easily assembling the entities into the system model, and serves as a key interaction point between the modeler and the VTB software.
* The Solver, which is responsible for the computational part. The VTB solver actually solves the system model using many different techniques and methods. The VTB Solver incorporates several different problem oriented solvers (Resistive Companion, Signal, Real-Time, Uncertainty, etc.) and automatically picks the appropriate solver needed to solve the specific problem.
* The Entities, which are the models of the particular devices. Some examples of entities are resistor, capacitor, inductor, motor, integrator, transfer function, etc. Entities contain specific information needed by the VTB solvers to solve the problem.
* The Visualization Engine, which is responsible for visual representation of the results of the simulation. The VTB Visualization Engine is highly sophisticated software that is capable of rendering 3-D models and animations and plotting 2-D waveforms.