Scilab/C2/Xcos-Introduction/English-timed

Time	Narration
00:01	Welcome to the spoken tutorial on Xcos: Scilab Connected Object Simulator.
00:07	Xcos is a Scilab package for modeling and simulation of dynamical systems. It includes both continuous and discrete systems.
00:17	In this tutorial you will learn What is XCOS. What is palette. Build block diagrams in Xcos
00:26	Setup the parameters of blocks. Setup the simulation parameters. Simulate the constructed block diagram.
00:35	To practice this tutorial, Scilab should be installed on your system.
00:40	I am using Ubuntu Linux 12.04 and Scilab version 5.3.3 for demonstration.
00:48	Open the Scilab console window on your computer.
00:52	Go to applications and select XcosOR Type xcos in your Scilab console window and press Enter
01:02	By doing this, two windows will open. The two windows arePalette browser and Untitled-Xcos window
01:14	In Palette browser, you will find different types of blocks Commonly Used Blocks Continuous time system blocks Discrete time systems blocksand many more.
01:26	The other window, Untitled-Xcos is blank, with grids.
01:31	We will now simulate a first order system with a step input.
01:36	To begin, I will select a transfer function block from the Continuous time systems palette.
01:43	Drag this block to the Untitled-Xcos window.
01:48	Select the required source in the Sources palette. I will scroll down and use the STEP FUNCTION block.
01:56	I will drag and place it before the transfer function block.
02:01	Similarly, the output is displayed using the CSCOPE block, which is available in Sinks palette.
02:08	The CSCOPE block is placed after the transfer function block.
02:13	The red input port in CSCOPE denotes that this block is an “event driven” block.
02:19	It needs an event input for execution.
02:22	An event generator block is available in the Event handling palette. The name of this block is Clock underscore c.
02:34	Drag and place this block above the CSCOPE block.
02:39	We have collected all the required blocks to do the simulation.
02:44	Let us now connect the blocks together.
02:47	Select the output port of step function block and connect it to the input port of the transfer function block.
02:55	Notice that the selected input port gets highlighted in green colour.
03:00	Similarly, connect the remaining blocks as shown.
03:05	Now we will set the parameters of each block.
03:10	First, go to the step block and double-click on it.
03:14	A pop up window appears, asking for the value of Step Time, Initial Value and Final Value.
03:23	Step Time is the time at which the step change will occur.We will keep it as 1, which is the default value.
03:32	Initial Value is the initial output value of the step function. We will keep it as 0, which is the default value.
03:41	Final Value is the output of the step function, after the Step Time is lapsed.We will change it to 2.
03:50	Click on OK.
03:52	Follow the similar procedure to configure any other block.
03:56	For transfer function block, the following configuration is required. Numerator value in laplace domain has to be entered.
04:05	We will keep it as 1, which is the default value.
04:09	Denominator value in laplace domain has to entered. We will change it to 2 asteric s plus 1.Click on OK.
04:20	Double click on CSCOPE block, to configure the following parameters.
04:25	The value of Ymin and Ymax should be set, depending on the range of the value, of the variable to be plotted.
04:34	Set the value of Ymin to 0.
04:38	Since I have given step input as 2, to display the output on graph, I should change the Ymax to any higher value.
04:46	We will change it to 3.
04:50	Make a mental note of the default value of the refresh period.The default value is 30.
04:57	We will keep the other parameters unchanged.Click on OK.
05:02	Now go to the Simulation in menu bar and click on Setup.
05:08	A pop up window appears.
05:11	We will change the value of Final integration time.Final integration time decides how long the simulation will run.
05:20	Recall the value of refresh period of the CSCOPE block.
05:24	I will keep the value of Final integration time equal to the value of refresh period of CSCOPE blockSo, I will change it to 30.
05:34	Keep the other parameters unchanged. Click on OK.
05:39	Now press Control S to save the file, with a suitable file name.I will save it as firstorder.xcos
05:50	To start the simulation, click on the Start button, available on the menu bar of Xcos window.
05:58	A Graphic window will open, showing the step response of the first order transfer function.
06:04	We can save this plot as an image file.
06:06	To save the graph, go to the File menu and click on Export to option.
06:12	I will name it as firstorder.png and click on OK
06:20	There are certain parameters which we chose to keep as the default value. These can be changed.
06:26	For example In the Clock underscore c block, the period, which means the sampling period and initial time can be set.
06:36	In the CSCOPE block, the output window number, position, size, buffer size , graph color etc can also be set.
06:46	Pause the video here and solve the exercise given with the video.
06:52	Simulate a second order transfer function with damping ratio of 0.5 and angular frequency equal to 1.
07:01	Try changing the color of output graph.
07:04	Using the first exercise, plot the Step input and the output in a single plot window.
07:11	Now let us summarize.In this tutorial we have learnt to: Create Xcos simulation diagrams using the palette browser Configure each block as per the simulation requirements
07:22	Setup the simulation parameters Save the output plot.
07:26	Watch the video available at the following link It summarizes the Spoken Tutorial project. If you do not have good bandwidth, you can download and watch it
07:37	The Spoken Tutorial Project Team Conducts workshops using spoken tutorials Gives certificates for those who pass an online test
07:46	For more details, please write to contact at spoken hyphen tutorial dot org
07:52	Spoken Tutorial Project is a part of the Talk to a Teacher project. It is supported by the National Mission on Education through ICT, MHRD, Government of India
08:02	More information on this Mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro
08:12	Hope you found this tutorial useful. This is Rupak Rokade from IIT Bombay signing off. Thank You.

Contributors and Content Editors

Pratik kamble, Sandhya.np14