The ECN No Name Newsletter is no longer being published. This is an archived issue.
[previous article] [next article]Edward J. Delp
SIMULINK is an extension of MATLAB. It simulates dynamic systems using a block diagram approach. One uses SIMULINK by manipulating blocks and connections among the blocks, instead of using mathematical expressions as in MATLAB. A user can define a block function or use an extensive library of function blocks. SIMULINK will simulate both continuous and discrete time systems. Input/output can be performed to MATLAB functions or variables or to a data file. The system is very flexible and extensible. The program is not difficult to use once some initial things are set up.
SIMULINK runs on the SUN4 systems under MATLAB 4.0 or higher. It is a separate module/toolbox that ECN has obtained as part of MATLAB. To use SIMULINK you must first start up MATLAB. MATLAB is kept in the /usr/ecn directory under SUN OS 4.1.X and in the /usr/opt/bin directory under SOLARIS 2.X. These directories are in the ECN default command search paths. If you have a customized search path in your .login or .cshrc, you may have to update your search path. You must run X windows or OpenWindows to use SIMULINK.
matlab to start up MATLAB. If you encounter a
problem starting MATLAB, you should consult your site specialist.
After MATLAB starts, type simulink at the prompt.
You are now running SIMULINK. You will get a transparent window frame established, click left on the mouse and the window will become opaque. This control window has the various SIMULINK blocks and options. To start a new problem move the cursor to the label "File" and click with the left button to pull down a menu. Click left on NEW and wait for the window to start up.
To examine any of the Block library, double click left on the block. For example, once you have a new window open, double click left on the "sources" block. A window of sources (input functions) will appear. Click left and hold on "sinewave." Pull the sinewave block to your new window and release. Double click on that sinewave box and you will now be able to see the sine function parameters that you can set.
Go back to the main blocks window and double click left on "sinks" and then pull the "scope" block into your problem area. This is a general output device that simulates an oscilloscope; double click on it to see the parameters you can change.
The output of the sinewave block can be connected to the input of the scope and the simulation can be started. To start the simulation, click left on "Simulation" and click left on "Start." (This simple example is contained in the file /home/stargate/bin/sig/simulink). When running a simulation, reset the simulation parameter (by clicking left on "Simulation" and then going to "Parameters") to:
Min. Step Size = 0.001
Max. Step Size = 0.25
All other parameters can be left alone. Note that the parameters
defaulted and/or suggested in the manual will not work! To stop
the simulation, click left on "Simulation" and click left on
"Stop."
For more information, users should consult the SIMULINK User's Guide located in major terminal rooms and Siegesmund Engineering Library. To avoid confusion concerning manuals, remember that SIMULINK evolved from SIMULAB and the manual still has the original name on it.
HTML