CAD softwares have a command line prompt where commands are “issued” and the status of a command is reported. When you select a command from the menu or toolbar, that command name is sent to the command line and is executed. Before most commands can begin, all other commands must be terminated. The exceptions are referred to as transparent commands. The easiest way to see if no commands are running is to look at the command line. If it displays Command: no commands are currently in progress.
When you are required to press the Enter key in CAD, you can use the Enter key on the keyboard or you can press the spacebar or click the right mouse button.
Pressing the Enter key will perform different operations depending on your location within the CAD software. If you are in the process of running a command, the Enter key will end the command (if there are no available options) or it will select one of the options available (see below). If you are at the command line Command: prompt, pressing the Enter key will repeat the last command.
As mentioned above, the right mouse button can be used as enter. However, you can set the right mouse button to perform different functions as well. When you click the right mouse button, you will get a drop down list of the options and can select the desired one. Move the cursor the desired option and click on it with the left mouse button.
For commands that provide no options, the Enter key (or spacebar or right mouse button) will end the command you are using. Also, when a command is issued in CAD, this action will also automatically end the previous command. However, there are exceptions to these two rules.
To avoid any problems with using the above methods to end a command, you can press the Escape (Esc) key. For example, if the command line displays something other than Command: or if a command you want to run does not start because you are using another command, you will want to end the command and return to the command prompt. Using the Escape (Esc) key will accomplish this every time.
Note: Some commands have several optional levels which will require the escape key to be pressed more than once.
If you accidentally select a location on the screen and start a selection window, the command prompt will prompt for another corner. Either select another point on the screen to finish the selection (not advised) or press the Esc key to return to the Command: prompt.
When any command is issued, the command line acts as a status bar that will show the available options and “ask” for input from you.
When there are options for the command you are currently running, these options will be shown on the command line with capital letters in the option name. To use one of the options, type the capital letter(s) at the prompt. For example, if you issue the Zoom command, the command prompt will show All/Center/Dynamic/Extents/…<Realtime>: To select the Dynamic option, type D at the command line, then press the Enter key. If you do not input an option and just hit enter, you will be selecting the option that appears in the <> brackets. For the example shown, that is the Realtime Zoom option.
Several commands in CAD software can be run transparently. This means that they can be performed while another command is running. For example, if you are in a command and are trying to select something in the drawing but it is too small to see, you can use the zoom command transparently. Zoom to the area where the object is, then select the object without ending the initial command. The most commonly used commands are the View commands of Zoom and Pan, and the Properties commands including the Layer dialog box.
To issue a transparent command, type an ‘ (apostrophe) before the command name. For example, ‘Z would be transparent zoom. Note that many commands will automatically be assumed to be transparent if they are issued from the toolbar while another command is running.
When you are in a command that is running transparently, this will be indicated with a >> at the far left of the command line preceding any options or other text. When a transparent command is complete, you will return to the command you were previously running. If you are in a transparent command and want to end the command to get back to the command prompt, you will need to press the Esc key twice.
Note: If you select a View command while running another command, the other command will not end. You will be running the View command transparently. This is one of the exceptions to the rules for ending a command. If you do not want to run the View command transparently, you need to complete the other command or end it by pressing the Esc key.
When you are required to press the Enter key in CAD, you can use the Enter key, the spacebar on the keyboard or click on the right mouse button.
When you press the Enter key at the command line Command: prompt, you will repeat the last command.
The Escape key (ESC) key can
be used to cancel any command. Some commands may require pressing
the Escape key more than once.
Undo reverses the effect of the previous command. Type U or use the shortcut Ctrl+Z to run Undo.
Redo reverses an UNDO command. You must use
the UNDO command before you can use the REDO command. Type
REDO or use the shortcut Ctrl+Y to run Redo.
Moves selected entities to another location
in the same drawing. Type M to run the Move command.
The command line changes as a command is
running. When there are options available for the command you are
running, they will display at the command line. To select one of
the options, type the capital letter(s) in the name of the option
and press the Enter key.
Most commands in CAD software require the selection of objects. When you need to select objects, the command line will prompt Select objects:. When you are at this prompt, your next step will be to create a selection set. While creating the selection set, the prompt Select Objects: repeats and you can continue to select objects until you press the Enter key, at which time the command you are using will continue and use the objects selected.
There are several ways to create a selection set from the Select objects: prompt. With all selection methods, the number of objects selected will be displayed in the command line along with any objects that were duplicated. Following are the most commonly used methods for creating a selection set:
A single selection is made when you move the object selection target to an object on the screen and click on it. The selected object will highlight and the select objects prompt will return. The cursor changes to a small square when the command line displays Select objects:.
A Window will select all objects completely inside of the rectangle drawn. Create a window by selecting a point on the view screen and then moving the cursor right. The window will display as a solid rectangle. You can also create a window by typing W at the select object prompt. In this case you can move the cursor to the left to create the window.
After you select several objects, they will be temporarily stored as a selection set. Should you want to re-use the same objects that were selected by the last command, you can type P at the Select objects: prompt.
If you select incorrect objects, you can type R to remove objects from the selection set. When you are in Remove mode, the prompt will be Remove objects:. Click on the objects that you do not want to include in your selection. To return to select or add mode, type A at the command line.
Objects may also be selected before issuing the command and receiving the Select objects: prompt. This selection will turn on CAD “grips.” Grips appear as small blue squares in the drawing. All objects with grips will be used when a command is issued. Grips are turned on similar to selecting objects as described in the previous section, but with the command line at the Command: prompt, not the Select Objects: prompt. You can select single objects by clicking on an object with the standard cursor or you can select multiple objects by clicking in the view where there are no objects, then creating the window (right) or crossing (left). To remove grips, press the Esc key twice.
Grips can also be used to edit or change the location of objects in the drawing. Move your cursor to a grip and click. You should notice the cursor “snap” to the grip. The grip will turn from blue to red. The object grip is now attached to the cursor so you can move the object to the desired location and release it by clicking again.
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In the Layer dialog box, you can highlight several individual layers to perform actions on at once by holding down the Control key and clicking on the desired layers. You can also highlight a continuous range of layers by highlighting one layer, holding down the Shift key, and clicking on another layer. All layers between the two will be selected. To select all of the layers, hold down the CTRL key and press A on the keyboard.
To turn layers on/off or freeze/thaw, you can also use the drop list on the toolbars. When you click on the symbols in the list, the layer’s status will be changed appropriately.
The current layer will be the one shown in the Layer drop list box. You can change the current layer by selecting the desired current layer from the drop list. You can also use the Set Current Layer button and select an object on the layer. The layer the object is on will become the current layer. Finally, you can highlight a layer in the Layer dialog box and click on the Current button to make the highlighted layer current.
You cannot freeze the current layer, but you can turn that layer off (not recommended).
To change the properties of an object in the
drawing, use the Properties button on the toolbar or the Change
command from the command line. This command will allow you to
change the layer an object is on, the color or linetype of the
object. The color and linetype can be set to bylayer or to a
specific setting. Bylayer means that when the property for a layer
is changed, so does the property for the object. For example, the
specific setting of an object may be the color blue. No matter what
color you set for the layer the object is on, that object will be
blue.
If this IntelliCAD Properties toolbar (or
any toolbar) is not displayed, you can open it using the Toolbars
dialog box. Type toolbar at the command line or
right-click on an existing toolbar for toolbar options.
The Layer dialog box is used to modify layers properties (color or linetype) or status (on/off, freeze/thaw).
Key-in: LA
Toolbar:
The Current Layer is the layer that you are on and will be working with. The Current Layer is the one shown in the Layer drop list. For example, in the above toolbar illustration, the Current Layer is Water.
Toolbar: 
The Change command allows you to modify the properties of an object, such as layer and color.
Key-in: CH
Toolbar: 
Note: Panning and Zooming is made easy if your mouse has a center wheel. You can use it to zoom in and out by rolling the mouse wheel up or down. By holding the center wheel down on the mouse, you can pan in any direction.
Type P for Pan then click and hold
the mouse on the point from which you want to move the display.
Drag the mouse to the desired area, then release the mouse.
Typing Z for Zoom will give you several options: To specify the scale, enter the magnification value. To zoom in, choose In. To zoom out, choose Out. To display the entire drawing, choose All. To view a window defined by a center point and the magnification value or height, choose Center. To display the drawing extents, choose Extents. To view a window by selecting the desired area in the drawing, choose Dynamic. To view a window defined by the left point and the magnification value or height, choose Left. To return to the previous display, choose Previous. To view a window defined by the right point and the magnification value or height, choose Right. To view a window defined by specifying two (opposite) corners, choose Window.
For additional assistance on general CAD software basics, please
visit our Knowledge Base at www.carlsonsw.com/support/knowledge-base/
or contact one of our Carlson College members listed here:
www.carlsonsw.com/support/carlson-college/carlson-college-members/.