The objective of this tutorial is to acquaint the student with the basic tools needed to use the SIMULINK package on the Unix workstations of the Rensselaer Computing System (RCS). SIMULINK is an extension to MATLAB which uses a icon-driven interface for the construction of a block diagram representation of a process. A block diagram is simply a graphical representation of a process (which is composed of an input, the system, and an output).
Typically, the MATLAB m-file ode45 is used to solve sets of linear and nonlinear ordinary differential equations. The ``traditional'' numerical methods approach is used, e.g. supply the equations to be solved in a function file, and use a general purpose equation solver (linear or nonlinear algebraic, linear or nonlinear differential equation, etc.) which ``calls'' the supplied function file to obtain the solution. One of the reasons why MATLAB is relatively easy to use is that the ``equation solvers'' are supplied for us, and we access these through a command line interface (CLI) (aka the MATLAB prompt, >>). However, SIMULINK uses a graphical user interface (GUI) for solving process simulations. Instead of writing MATLAB code, we simply connect the necessary ``icons'' together to construct the block diagram. The ``icons'' represent possible inputs to the system, parts of the systems, or outputs of the system. SIMULINK allows the user to easily simulate systems of linear and nonlinear ordinary differential equations. A good background in matrix algebra and lumped parameter systems as well as an understanding of MATLAB is required, and we highly recommend that the student thoroughly reads and works through this tutorial. Many of the features of SIMULINK are user-friendly due to the icon-driven interface, yet it is important to spend some time experimenting with SIMULINK and its many features. Dynamic simulation packages (such as MATLAB, SIMULINK, etc.) are being used more and more frequently in the chemical process industries for process simulation and control system design. After completing this tutorial, the student should be able to ``build'' and simulate block diagram representations of dynamic systems.