LESSON 4-8

LESSON 4-1	AUTOCAD TEMPLATE FILES
LESSON 4-2	USING OSNAPS IN AUTOCAD
LESSON 4-3	LINETYPES AND LINETYPE SCALE
LESSON 4-4	AUTOCAD FILE FORMATS
LESSON 4-5	GRIP EDITING
LESSON 4-6	AUTOCAD'S INQUIRY TOOLS
LESSON 4-7	XREF'S (EXTERNAL REFERENCES)
LESSON 4-8	SYSTEM VARIABLES
LESSON 4-9	TABLES
LESSON 4-10	INTRODUCTION TO SHEET SETS
LESSON 4-11	MODIFYING AND CREATING DIMENSIONS
LESSON 4-11a	TYPES OF DIMENSIONS
LESSON 4-12	INTRODUCTION TO CUSTOMIZING AUTOCAD

Topics covered in this Lesson:

System Variables

AutoCAD is a complex program and one of its major selling points is that it is highly customizable. Every user will use AutoCAD differently. Some use icons, some use command line prompts. Each drawing is also different. You may have different text heights, or dimension styles from one drawing to the next. To keep track of these different parameters, AutoCAD uses a large number of system variables to do this. You have recently used one system variable: LTSCALE. This could have been changed in the Linetype dialog box, but typing LTS is easier and quicker. A system variable is a configuration setting that can be changed by the user. Some system variables can not be changed, these are known as read-only variables. Here is an example of each: SYSTEM VARIABLE CURRENT VALUE TYPE TEXTSIZE 0.200 USER CONFIGURABLE ACADVER "16" (read only) READ ONLY Most of AutoCAD's system variables are changeable. This allows for quick customization as well as easier programming. Once you have used AutoCAD for a while, you may find that it is easier to redefine a system variable than to go through a dialog box to get the same result. In some cases, the only way to make these changes is through the system variable itself. Unfortunately, there are no shortcuts for entering these, you have to either remember them, or have a list nearby. Some of them are quite straightforward as to what they do, but some are rather cryptic and make it difficult for memorization. **NOTE: In Level 3 (3-D), you were working with system variables to some degree. Warning: Don't change system variables unless you know exactly what you're doing. To see a list of all of the AutoCAD system variables, follow these steps: Command: setvar <ENTER> Variable name or ?: ? <ENTER> Variable(s) to list <*>: <ENTER> It shows you what the settings were for a particular drawing at a specific time. The list also shows you which system variables are read only. For a listing of these in AutoCAD 2008