Using Dynamic Blocks and Tables - AutoCAD 2011 and AutoCAD LT 2011: No Experience Required - page 440

using Attributes for a Grid
In Chapter 8, you added a series of gridlines to your cabin. These gridlines were
placed at the centerlines of structural components such as walls or columns.
Especially in larger plans, these gridlines often provide critical points of reference
for collaborating with contractors and other consultants over the phone. What
makes the structural gridlines so useful is the way they're labeled. Gridlines are
most often labeled using a circle or hexagon with numbers running in one direc-
tion (horizontally or vertically), and letters running the other. Because more
elaborate floor plans will likely have multiple closets, it's rather ambiguous to ask
someone to look at the closet in a plan. Instead you might say, “Have a look at the
closet near gridline intersection C2.”
Just as the gridlines help make your printed plans more useful, blocks can do
the same inside your drawings by combining multiple related objects into a sin-
gle AutoCAD entity. Because each grid needs to have a unique letter or number,
creating a static block as you did in Chapter 7 won't work for this application.
Instead you need a block that can display a unique number or letter for each
block insertion. You can achieve this level of interaction with any block by add-
ing attributes to its definition.
A simple but handy use of attributes is to make the letter or number in the cir-
cle an attribute and then make a block out of the attribute and circle. By redoing
the grid symbols in the cabin drawing, you'll learn how to set up attributes and
create a new block that can be used in any other drawing. Because you'll define
the block as an annotative block , the grid label blocks you create will not be scale
dependent.
1. Open 08A-FPLAY4.dwg . The drawing consists of the floor plan with
a structural grid, notes, and a title block.
Make sure the A-GRID layer is current, and then freeze the
A-ANNO-TTLB and A-ANNO-TTLB-TEXT layers.
TIP You've already seen how the -LAYER command can be used to
create new layers, but it can also be useful layer management. Instead of
freezing the two a-aNNO-ttLB layers individually, try entering -LAYER ↵
F ↵ *TTLB* ↵↵ . this command sequence tells autoCaD to freeze all ttLB
layers at once. the asterisk ( *) is a wildcard character that tells autoCaD to
look for any layers with TTLB in their names—and in this case freeze them.
2. Zoom into the floor plan, keeping the grid visible. In this case, the
letters run horizontally across the top and the numbers run vertically
along the side.