Can one create electronic schematics

I am an experienced electronic CAD user, but an AutoSketch
(Rev 9) newbie. I am trying to use it to create a schematic
diagram, from which I would like to derive a hard-copy
drawing and Excel-compatible bill of material (BOM).

I was unhappy with the electronic symbols in the libraries
supplied and tried to create my own. I have hit the wall
when it comes to assigning to individual components what
electronic CAD programs call "attributes" or "properties."

This is a set of text strings assigned to a variable
associated with the symbol type, which can be different for
each symbol instance on the drawing. The closest thing I
can find to this concept in AutoSketch is the "field."

Typical components with different symbol graphics would be:
- Capacitor
- Resistor
- Transistor

I want to store a manufacturer's part number (P/N) with
every symbol in my drawing, which appears in an appropriate
column of the BOM. Furthermore, the transistor's part
number also is visible on the schematic, while that of the
resistor and capacitor are not.

I will extend this example to add a value for each resistor
and cap (2.2 k, 0.001 uF), appearing on the drawing and the
BOM, but transistors do not need this attribute at all.
Finally, capacitors and transistors have a voltage rating
(e.g. 16 V) that I want to place on the BOM only, while most
resistors don't need this field. The relationships are
slightly complex, so I will reduce them to tabular form:

Volt-
Symbol P/N Value age
---------- ----- ----- -----
Capacitor BOM D/B BOM
Resistor BOM D/B .
Transistor D/B . BOM

Traditional CAD programs allow me to put BOM-only attributes
on a different layer than drawing+BOM attributes, and to
turn that layer off during printing, or to set the font size
to 1 point, making it a single dot when printed.

It is also critical that every attribute of every instance
of Resistor to be independent of all other instances, or my
drawing can have 3 resistors, whose Value fields would be
100 ohms, 3.9 kohms, and 560 kohms, respectively.

When I tried to implement this in AutoSketch I found:
- The program only lets me add new fields at the level of
the drawing, i.e. every symbol on that drawing must
accept a definition of every field possessed by any of
its neighbors.
- I can only modify a field for a single symbol type (i.e.
all the resistors) at a time.
- I can't get the fields to appear on the drawing at all.
- When I attempt to generate a bill of materials, the
report creates one line item for every symbol I placed
there. I can't make it group all the 1 k resistors on a
single line and give me a quantity greater than 1.

Any suggestions, or am I trying to cram a square peg in a
round hole?
============================================================
Gary a.k.a. bibliognost

 

Hi Gary

Yes, you can do schematics with Autosketch. But is a lot of work compared
to a dedicated schematic program.
I am an electronics tech, and I have produce publishable schematics with
this program, and have used the database
to do parts lists from schematics. I mainly use it for layout of test
fixtures and PC boards, and documentation illustrations.
But this can be handy, especialy when working with others who use dwg/dxf
formate schematics.

Parts: In ten + years I think I may have used 10-12 of the furnished
symbols. Mostly its make your own, but if you open a dfx or dwg schematic
with parts, you can import them into AS.


To get a quick idea of how the database/formula text work look at some of
the ISO templates.
here is a copy of a previous post I made about embedded text.


Open a new file with the ISO_A4 template. Select any of the
lines in the drawing. The Edit bar will show that what you
selected is a symbol also called ISO_A4 (just to make things more
confusing).

Zoom in on the XXX text field in the lower left corner. Now
explode the symbol. The XXX changes to %dB("OWNER"). There is
still one more layer. Click on %dB("OWNER"), and uncheck the
mark next to Formula. The text changes to <%dB("OWNER")>. This
is the format you have to use to embed text from database entries
in symbols.

After you add or modify the formulas (making sure to check the
Formula box ), you have to select all the lines and text and
re-save as a symbol.
In the help files see:
Embedding Formula Text in Symbols
To create a symbol containing formula text
Working with Formulas

If you deside to go ahead, reply and I will try to come up with a few hints
and a list of "gotchas" this weekend.

good luck
Rod

 

I am now in a position to agree with you.

I opened up the template you suggested, exploded the
indicated symbols and found the entities as you described
them. I'm afraid I didn't learn much from them.

I'm guessing I should group the elements of the symbol
graphic first, then group all the text fields with that,
then select, then define symbol (to custom library).

Only found the first & last topics. It appears there is
something magic about the construct <%db(variable)>, but I
am not chanting the right words. Also, in the sample
template (ISO_A4) the variable is shown inside double quotes
("variable"). Is this significant?

The drawing I started with already had the fields:
- P/N
- RefDes
- Value

among others, and I tried to assign these to the %db()
formula. When I defined the new symbols, I had the
opportunity to assign values to all the fields defined for
the drawing, and when I brought the symbol back in from the
library, it was those definitions that were visible on the
drawing. They also showed up in the Report I generated. I
could find no way to edit them, once the symbol was placed
on the drawing.

That's it. According to the search engine, the string "db"
only appears once in the entire help system. I can't
imagine how the first AutoSketch user got past this.

Thanks for the boost, anyway.
============================================================
Gary a.k.a. bibliognost