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.

Lou Russo, Howard P. Isermann Dept. of Chemical Engineering