Tips for Block Diagram Using
"Visio"
Prepared by: Santosh
K. Waddi, SPI Lab, EE Dept., IIT Bombay, 8th Oct, 2012
1.
For creating new
drawing in File menu, select New Drawing (Metric) in New option. "Metric" will give
dimension in mm and "US units"
will give it in inches.
2.
If the shapes
(circle, line, and rectangle) are not visible on the toolbar, follow the
following steps
i.
In Tool menu,
select Customize option.
ii.
In Customize
window, mark the checkbox Drawing inside the Toolbar tab
iii.
Select the
appropriate shape in the Drawing window.
iv.
For any other
shapes, type the shape name in the Search for Shapes window.
3.
Size of the block
diagram. Draw the figure to make full use of the page/column width. Therefore,
the horizontal width of the figure should be either full width or half width of
A4 paper (leaving the margins), and the vertical height can be as needed and
less than length of A4 paper. Full width: < 159 mm (210 mm - 2x25.4 mm), half
width: 75 mm. Figures drawn with this width can be generally pasted in the
document and presentation files without scaling. Try to draw the figure in the portrait
format. The landscape format should be used as the last option.
4.
Text font type. Arial
Narrow, Arial, or Helvetica. This assures clear readability at different levels
of scaling of the figure. For mathematical symbols, use Times New Roman (with
or without italics as per appropriate math notation).
5.
Font size for
text = 10. For good readability, use "Small
Caps" for text other than mathematical symbols. Text in
bold is better suited for presentations and is also acceptable in documents.
Therefore use all the text in bold. The text inside a text box should
preferably be center aligned.
6.
Box size.
Preferably use 20mm x 10mm boxes for blocks. This can accommodate two lines of
10 characters. Boxes should not have unnecessary variation in their sizes. The
size may be changed to indicate the complexity/importance of the block. The
material inside the box may be abbreviated if needed. The box size should not
be adjusted to fit the text.
7.
Block outline
thickness should match that of the text characters. For text in Arial Narrow,
font size 10, and style bold, the box line width should be set by selecting "Weight = 05".
8.
The inputs and
outputs of a block should be on opposite sides of the box. Control inputs
should be perpendicular to both input and output. A box should not be used to
turn the signal direction. For example, when the input is applied on the left
side of the box, the output should not be taken from the lower or upper side of
the box. Take it from the right side and then turn it downwards or upwards, if
needed.
9.
Two points can be
joined by a "line". A line can
be converted to "connector" for
routing around boxes. For converting a line to a connector, select the line. In
Window menu, choose Show Shape Sheet. Find the Miscellaneous section and then
set the ObjType cell = 2. This tells Visio to treat the shape as a routable
connector.
10. Line and arrow size. Preferably use line "Weight = 05"
and line ends "Begin or End = 05".
This keeps the line thickness and arrow size compatible with the box line
thickness.
11. Crossings and nodes. It is preferable to have line
crossings without jumps. A black dot should be used for nodes of 3 or more
lines. For placing the dot, right click on the line. In the Format menu, select
Line and choose Line ends "Begin or End
= 10".
12. Minimum spacing. Lines and boxes should have at least 4mm
separation. Text should be at least 1mm separated from nearest line or box. Arrow
head should be at least 6mm from the nearest bend in the line.
13. Adder and multiplier. Preferably draw a circle of 8mm
x 8mm size. Inside the circle, write '+' or 'Χ' with Font Type = Arial, Size = 12, and Style=Bold.
14. If there is an alignment problem, zooming (>400%)
can be used for high precision alignment.
15. You may go through the following example for sizes and
separation. It may also be used as starting point for a new block diagram.