3
E 2004/2/2Entering Command and Data Input
ENTERING COMMAND AND DATA INPUT
OBJECTIVES
General Objective: To understand and use the methods of entering command and data
input
Specific Objectives: At the end of the unit you will be able to :
Enter command by three different methods.
Create drawing by coordinate entry.
Use Direct Distance Input to create drawing.
Create a drawing by using Absolute Cartesian Coordinate.
Create a drawing by using Relative Coordinate.
Create a drawing by using Polar Input.
Explain the deferential four methods coordinate entry.
2.1HOW TO BEGIN A COMMAND
There are three possible methods for entering commands in AutoCAD depending on your preferences setting ( for the screen menu ). Generally any one of the three methods can be used to invoke a particular command.
1.KeyboardType the command name, command alias, or accelerator ( Ctrl ) keys at the keyboard
2.Pull-Down MenuSelect the command or dialog box from a pull-down menu.
3.ToolbarsSelect the command or dialog box by PICKing an icon ( tool ) from a toolbar
2.1.1Keyboard.
When you enter a command in a command window, AutoCAD either displays a dialog box or prompts you for further information. This line of Command text is termed the Command Prompt. The Command prompt asks you to specify coordinate value, command options, or any other data needed to complete the command. The following text is an example of the Command prompt for the PLINE command.
Figure 2.1 : Example of the Command prompt.
Once you are comfortable entering commands at the Command prompt, you can learn the command aliases, which are basic one- or two- or three- letter abbreviations of the commands. Many commands have an aliases, and learning these can help you work faster and more productively. A list of all the command aliases is located in the Help menu.
2.1.2Pull Down Menu
When you perform a Typical installation of AutoCad, you are presented with a menu bar containing 10 menus:
Figure 2.2 : Menu Bar with 10 menus.
These menus provide an alternate method of accessing command and dialog boxes other than the command prompt or toolbar button. They are term pull down menu because when you choose one with your left mouse button, the menu is display beneath its title, as if you were pulling the menu down from its title. The menu remains present until you click anyway outside of it.
2.1.3Toolbars
Another method of performing commands is through the various toolbar tools. There are many tools in the 21 toolbars, but those most frequently used, relating to file, edit and view, are found in the Standard toolbar, shown in the following figure:
Figure 2.3 : Standard Toolbars
To display other toolbars, you can access the Toolbar dialog box in the following ways:
Toolbar : Right click any currently visible toolbar
Menu : View > Toolbars
Command : TOOLBAR
The Toolbars dialog box is displayed as shown in figure below:
Figure 2.4 : Toolbars dialog box
Clik on the box to choose any toolbars you need to use. Then, clik Close button to end the session.
ACTIVITY 2a
FILL IN THE BLANK.
2.1 List three methods for entering command in AutoCAD R14. Explain.
i.
ii.
iii.
2.2 Give the steps to access the line command to draw a line by using the pull down menu.
2.3 How can we display the toolbar box?
Feedback To Activity 2a
ANSWERS.
2.1.
1.KeyboardType the command name, command alias, or accelerator ( Ctrl ) keys at the keyboard
2.Pull-Down MenuSelect the command or dialog box from a pull-down menu.
3.ToolbarsSelect the command or dialog box by PICKing an icon ( tool ) from a toolbar
2.2.Pull Down Menu:Draw > Line
2.3.Toolbar : Right click any currently visible toolbar
Menu : View > Toolbars
Command : TOOLBAR
2.2 CREATING DRAWING BY USING COORDINATE ENTRY
AutoCAD provides various commands that you use to locate points in the drawing plane. You can create a drawing by using Direct Distance entry, Absolute Coordinates, Relative Coordinates, and Polar entry methods.2.2.1Direct Distance Entry.
To enter point you can use a feature called direct distance entry. With direct distance entry, you can specify a relative coordinate by moving the cursor in the desired direction and then entering a distance.
Coordinate value are specified by moving the cursor to indicate a direction and then entering the distance from the first point. This is useful when you need to quickly specify a length. An efficient way to create object constrained to the current axes is to use direct distance entry combined with Ortho mode turned on.
Direct distance entry can used with all commands except those that prompt you to enter real values. This commands include ARRAY, MEASURE, and DIVIDE.
2.2.2 Absolute Cartesian Coordinate Input.
Absolute coordinate system can be used when you know the exact X and Y values of the point you want to place in the drawing window. The absolute coordinates method uses the Cartesian coordinate system to locate points in the drawing window. All points are measure from origin (0,0).
The Cartesian coordinate system has three axes X, Y, and Z that are used to locate points and create objects. The Cartesian coordinate system uses distances ( in unit ) to locate points along intersecting axes, the horizontal X axes and the vertical Y axes. The intersection of these axes called the origin, where X = 0 and Y = 0 denoted as ( 0,0). These axes divide the coordinate system into four quadrant each having positive, negative or positive and negative X and Y values.
You can draw a line by starting at the 0,0 and end at the point 3,4
Figure 2.5 : Two dimensional Cartesian coordinate system.
World Coordinate System ( WCS )
When start a new session, by default you enter the World Coordinate System (WCS). This system consist of a horizontal X displacement, a vertical Y displacement, and a Z displacement that is perpendicular to the XY plane. The Z displacement is used for 3D drawing. All X,Y and Z coordinate values are measured from the origin. The origin is located at the intersection of X, and Y axes (0,0). The origin is originally located in the lower left corner of a drawing. The WCS cannot be redefined, and all other user coordinate system are based on the WCS.
User Coordinate System ( UCS )
The User Coordinate System ( UCS ) lets you establish your own coordinate origin. The UCS is movable, meaning that the origin can be moved to any desired orientation and its axes can be rotated. The UCS icon is displayed by default in the lower left corner of the drawing window. The icon is used to help better understanding the location and orientation of the movable UCS. The X and Y arrows point in the positive direction of the axis. The W in the following figure indicates the WCS is current. The UCS icon is shown in the following figure:
Figure 2.6 : UCS icon
Method for invoking the UCS command include:
Toolbar : Standard
Menu : Tools > UCS
Command : UCSRelative Cartesian Coordinate Input.
A relative Cartesian coordinate is entered as the X and Y distance from the last point you specified. Use relative X,Y coordinate when you know the position of a point in relation to the previous point. For example, to locate a point at a relative direction of 4,5 from the first point specified, precede the next coordinate with the @ symbol. The following example demonstrate how to enter a relative coordinate:
At the command prompt, enter line.
In response to the From point command prompt, enter 0,0
In response to the To point command prompt, enter @4,5.
Figure 2.7 : example to entering relative coordinate
Polar Input
A polar coordinate is entered as a relative distance and angle from an absolute coordinate or the last point specified.
To enter a polar coordinate, enter a distance and an angle, separated by an angle bracket (
