Xfig/C2/Feedback-control-diagram/English-timed
From Script | Spoken-Tutorial
| Time | Narration |
| 00:00 | Welcome to the spoken tutorial on feedback diagram creation using Xfig. |
| 00:07 | In the spoken tutorial on block diagram creation, we created the diagram shown here. |
| 00:14 | We will refer to it as the blocks tutorial. |
| 00:18 | Please master the blocks tutorial before starting the current one. |
| 00:22 | In this tutorial, we will explain how to create block diagrams of the type shown on this page. |
| 00:31 | I shall use Xfig version 3.2, patch level 5. |
| 00:37 | We will begin with "block.fig" created in the blocks tutorial. |
| 00:43 | Let us go to Xfig. |
| 00:47 | Let us choose the File, then Open. |
| 00:52 | In the entry box, we can enter "block" and press Open. Or double-click on “block.fig”. |
| 01:04 | Using the Save as option on File, we will save this figure as "feedback". |
| 01:24 | We now have the file "feedback.fig". |
| 01:28 | Let us put the grids on by clicking on the Grids. |
| 01:34 | The scroll bar on the right can be used to move the canvas up or down. |
| 01:41 | The role of each mouse button is shown on the top right hand side. |
| 01:46 | This role depends on the activity. |
| 01:49 | To illustrate this, let me take the mouse to the vertical scroll bar. |
| 01:55 | Observe the comment next to the left button. |
| 01:59 | I cannot move the mouse to show this. It is because, the role of the buttons will change if I move the cursor away from the scroll bar. |
| 02:08 | The left-button moves the canvas up and the right-button moves it down. |
| 02:17 | Instead of clicking the left or right button, we can also click the centre button, hold and drag the canvas up or down. |
| 02:31 | In a similar way, you can move the canvas to the right or left, using the scroll bar on the top. Left, right.. |
| 02:44 | I will now move the box to the centre by clicking the middle button, holding and dragging the canvas to the centre. |
| 02:57 | As I release the mouse, the box gets moved to the centre. |
| 03:03 | Let us now create the feedback diagram starting from this block. |
| 03:08 | Let us copy this box. |
| 03:13 | Click on the box and select it. |
| 03:16 | Move the mouse to the new location and click. |
| 03:27 | Let us now put some text. |
| 03:29 | Let us click the text-box, indicated by T, from the left hand side panel. |
| 03:37 | Let us choose the size of the text. |
| 03:43 | Move the mouse to the value-box and enter 16. |
| 03:51 | Click Set. |
| 03:53 | Let us click the Text Just button in the attributes panel. |
| 04:02 | Let us choose the centre alignment. |
| 04:05 | Let us click at the centre of the first box. |
| 04:11 | Sorry, I did not choose the correct position. |
| 04:15 | I will click at a different location to move the cursor away. |
| 04:19 | I will then click at the correct position. |
| 04:27 | Let us now type the text “Control” and click the mouse. |
| 04:35 | We would now want to enter some more lines with arrows. |
| 04:40 | Let us choose the POLYLINE button. |
| 04:43 | Let us select the Arrow Mode button from the attributes panel and select the second option. |
| 04:53 | Let us click the Arrow Type button and an arrow head. |
| 05:00 | Let us click at the point where we want the line to start. |
| 05:08 | Let us move the mouse to the end point of the desired line. |
| 05:14 | Let us now click there with middle mouse button. |
| 05:20 | The line is created with an arrow. |
| 05:25 | I want to place a circle. |
| 05:27 | Let us choose the circle on the left from the left hand side panel. |
| 05:33 | We will place it to the left of the first box. |
| 05:37 | Click the mouse. As I move the mouse, the circle becomes bigger. |
| 05:47 | When we get the right size, let us release the mouse button. |
| 05:54 | Oops, the circle is larger than what I wanted. |
| 05:57 | I can undo this operation, using the Edit button at the top. |
| 06:02 | We can also delete this object, using the Delete button on the left hand panel. |
| 06:10 | Let us do that now. |
| 06:14 | A skeleton with cross hairs appears. |
| 06:18 | All key points of all objects also appear. |
| 06:22 | Move the cross hairs to a key point that indicates the circle and click. |
| 06:32 | In case a wrong object is deleted, no need to panic. |
| 06:35 | You can undo it: Click the Edit button, hold, go to Undo and release the mouse. |
| 06:44 | If some objects are closely placed, you may have difficulty in choosing them. |
| 06:49 | You can solve this through the zoom feature. |
| 06:55 | Click the View button on the top left hand side, hold and choose one of the zoom options. |
| 07:00 | Let me release the mouse at Zoom to fit the canvas. |
| 07:04 | Now it is easy to discriminate between the objects. |
| 07:08 | Let me delete the circle now. |
| 07:12 | Let me unzoom. |
| 07:20 | I will move the diagram to the centre with the use of scroll buttons. |
| 07:35 | I do not like to leave the delete symbol on because I can accidentally delete something else. |
| 07:41 | I can change this by choosing any other button. |
| 07:44 | Let me choose the left circle. |
| 07:47 | Let me redraw the circle. |
| 08:00 | I want to put another line from this line. |
| 08:04 | For this, we will first put a dot on the line. |
| 08:07 | Let us click the Library, on the left hand side panel. |
| 08:11 | The Library is indicated by a stack of books. |
| 08:15 | A dialog window opens. |
| 08:17 | Next to the Library, it says "None Loaded". |
| 08:20 | Let us click and hold. |
| 08:22 | A list of available libraries appears. |
| 08:25 | Move the mouse to the 'Logic' library and release the mouse. |
| 08:31 | Let us choose the small dot by double clicking on it. |
| 08:36 | The dialog window gets closed. |
| 08:38 | We see a cross hair along with the chosen small dot. |
| 08:42 | Let us place the dot on the line by clicking. |
| 08:51 | The cursor and the small dot show up once again, suggesting that we can place it at some other location also. |
| 08:57 | We do not want to place the dot at any other place. |
| 09:00 | Let us close it by clicking the right button of the mouse. |
| 09:05 | The right button does an undo operation. |
| 09:08 | In this case, dot selection has been removed. |
| 09:10 | Let us draw a line from this dot to the circle. |
| 09:15 | Let us select the Polyline. |
| 09:18 | Notice that the previous selections of Arrow Mode and Arrow Type have been remembered. |
| 09:24 | Within a session, Xfig remembers the parameter values. |
| 09:28 | Click at the dot. |
| 09:34 | Move the mouse to the bottom and click. |
| 09:41 | Now turn the mouse to the left, until at the bottom of the circle. Click. |
| 09:47 | Move the mouse to the circle and now click the middle mouse button. |
| 09:54 | Let us draw another line, to the left of the circle, by copying. |
| 10:08 | Let us now save this figure using the File button at the top left hand corner of Xfig and choosing Save. |
| 10:19 | Let us now Export the file. |
| 10:22 | Let us click the File button once again and choose Export. |
| 10:30 | Let us choose Language and then PDF. |
| 10:36 | We get the file "feedback.pdf". |
| 10:43 | Let us open this file through the command open feedback.pdf. |
| 10:56 | We now have the block diagram that we wanted. |
| 11:00 | We have completed our objective. |
| 11:04 | We have an assignment for you. |
| 11:08 | Substitute the blocks with different objects. |
| 11:13 | Try out operations such as rotate and flip. |
| 11:19 | View the file "feedback.fig" in an editor and identify different components. |
| 11:25 | Using the Library, create entirely different block diagrams. |
| 11:32 | Spoken Tutorial is a part of the Talk to a Teacher project, supported by the National Mission on Education through ICT (NMEICT), MHRD, Government of India. |
| 11:44 | More information on this mission is available at:http://spoken-tutorial.org/NMEICT-Intro |
| 11:53 | We welcome your participation and also your feedback. |
| 11:57 | This is Kannan Moudgalya, signing off. Thanks for joining. Goodbye. |
