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________________________________ From:
Robert<birmingham_spider@...> To: kicad-users@...
Sent: Sunday, June 10, 2012 8:00 PM Subject: Re: [kicad-users] Re:
Comments About Eeschema



Have you seen Bernd Wiebus's EN60617 (aka IEC60617) kicad library?



If it's correct (I have no reason to doubt that but I have nothing
to check it against, though maybe those Chinese sites are worth
exploring) I guess it would be a good place to start, though
personally I find Bernd's symbols too big. Is it the latest
standard?

Regards,

Robert.

Hi Robert,

Some of those symbols do comply with the IEC standard and many that
don't do comply with older standards. Anyway, as I said, what's
important is that people can read the schematics. I think Bernd's
symbols can't really be shrunk much more; I'd say his symbols are OK,
certainly usable, but most can be improved (for example, the purists
will howl about the line connecting the vertices of the inductor
symbols - and rightly so). The problem as usual is time; building a
good symbol set takes an awful lot, and at this point in time I'd
recommend waiting for KiCAD to go metric (internal units =
nanometers) before spending time building up standard symbols.
However, if you look at the symbols which come with KiCAD, very many
(I can't say 'most' because I haven't looked through the set and
counted the bad ones) are not only non-compliant with the latest IEC
specifications, but I don't recognize the symbols as IEC, IEEE, or
ASME - some of the symbols are such poor caricatures of standard
symbols that they will actually make a schematic difficult to read.


What I would like to see in the future is a standards-compliant
symbol set for KiCAD. This can start with an IEC60617 directory with
libraries classified according to form or function - that alone will
give us many of the symbols we typically use - and then people can
contribute other symbols but those symbols will need to be vetted
before they're put into the library tree; once you head down the path
of standardization you really can't afford any compromise - any
symbols which have not been vetted will have to go into a
'non-standard' directory branch.


This is all somewhat academic at the moment. KiCAD is certainly
usable as it is and although it would be great to start implementing
improvements, KiCAD also happens to be in a state of development
where it's probably best to hold back on making those improvements.

- Cirilo

On 10/06/2012 00:04, Cirilo Bernardo wrote:

________________________________ From:
Robert<birmingham_spider@...> To:
kicad-users@... Sent: Saturday, June 9, 2012 7:15
PM Subject: Re: [kicad-users] Re: Comments About Eeschema



I'm not sure what is the intention of this thread but please
remember that kicad is international and these are all US
standards. Component annotations are almost certainly
governed by an ISO standard.

Regards,

Robert.

Sure, but many of the ASME standards were transferred to IEC and
some later became an ISO standard - but having said that, many of
the symbols people created for EESCHEMA do not comply with
standards. For example, the MOSFET with a symmetric gate -
standards documents dating over 35 years ago were recommending
the asymmetric gate symbol and personally when I see a symmetric
gate symbol I want to hit someone with a large book. This is not
really a problem because people can still understand the
drawings. However, it's a good idea to move towards standards
compliance. On the down side, I think the best way to proceed is
to have a working group who spends time making up a new set of
compliant symbols, including existing symbols after confirming
that they comply with standards, and checking symbols other
people submit. This is not a small job; it's something I
wouldn't mind doing, but at the moment all my free time is going
into the 3D solid

model

issues which I believe is of far more value to users at the
moment than standards-compliant symbols. However, regarding the
comments on standard reference designators - that's something
which should be brought into conformance as part of the process
of making KiCAD a top quality tool.

- Cirilo

On 09/06/2012 07:14, Lawrence wrote:

John, I have been able to find the IEEE and ASME standards
online on the Internet. They are usually in PDF and some may
be freely downloaded for non commercial usage because they
are copywrited material. --For IEEE 315-1975 (R1993) "Graphic
Symbols for Electrical and Electronics Diagrams (Including
Reference Designation Letters)" see message number 11068 to
see where to go to get a PDF copy that can be downloaded.
This standard was withdrawn by ANSI as an American National
Standard (ANS) as of June 2004. The IEEE has this as an
active standard but there has been no activity on it since
being reaffirmed in 1993. --For ASME Y14.44-2008 "Reference
Designations for Electrical and Electronics Parts and
Equipment" I went to a Chinese Website<www.> and
ended up at<www.doc88.com/p-6030462696.html>. This is
viewable and maybe can be downloaded but the process is not
straight forward. --For ASME Y14.34-2008 "Associated Lists" I
also went to the Chinese Website<www.> and ended
up at<www.doc88.com/p-5990462641.html>. Again, this is
viewable and maybe can be downloaded but the process is not
straight forward.

Regards, Larry 9V1/WN8P

--- In kicad-users@..., John Hudak<jjhudak@...>
wrote:

LOL, well said! (I am not a developer in this effort, but
have been on others). I've often wondered this myself.
Having seen this lack of attention to standards in other
open src tools, I can guess at many reasons, ranging from
ignorance to arrogance to cost (acquiring some of those
standards requires real money). In many cases, there is
quite a lot of overlap between IEEE/ANSI/IEC/CENELEC etc.
OTOH, I am thankful for the tool.... I am very interested
in the response..... -John


On Wed, Jun 6, 2012 at 10:37 AM, Lawrence<lawrence_joy@...>
wrote:

**


To developers of Kicad and others. Comments about
Eeschema.

--Why are the X,Y coordinates upside down in the Y axis?
When I learned Cartesian coordinates the abscissa (X
axis) has positive values going to the right and negative
values going to the left with the ordinate (Y axis) with
positive values going up and negative values going down.
Quadrant I would have the 0,0 point in the lower left
corner. Do they teach this differently in Europe? It is
very confusing to me.

--Terminology for reference designators: A basic
reference designator has a class designation letter(s)
and a number. Class designation letters are 1, 2, or 3
letters, but if 3 letters are used the 1st letter will be
X as in XDS or XAR. For the complete reference designator
A1R7, the A1 is called the reference designator prefix
and for the complete reference designator A1PS1C3, the
A1PS1 are called reference designator prefixes. The Unit
Numbering Method of assigning reference designators is
covered by ANSI/ASME Y14.44-2008 (used to be ANSI/IEEE
200-1975).

--I have seen in many messages the term "multi-part
component" used. The terminology I know is
"mulple-element part" and is covered in ANSI/ASME
Y14.44-2008, Clause 2.1.4 Suffix Letter.

--The terminology I know calls a listing of parts a
"parts list (PL)" and is covered by ANSI/ASME
Y14.34M-2008 Associated Lists. In this standard it is
stated that "bill of material" is an obsolete term.

Just some ramblings.

Regards, Larry 9V1/WN8P

------------------------------------

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posting your question. Please post your bug reports here.
They will be picked up by the creator of Kicad. Please visit
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posting your question. Please post your bug reports here. They
will be picked up by the creator of Kicad. Please visit
for details of how to contribute your
symbols/modules to the kicad library. For building Kicad from
source and other development questions visit the kicad-devel
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Please read the Kicad FAQ in the group files section before posting
your question. Please post your bug reports here. They will be picked
up by the creator of Kicad. Please visit for
details of how to contribute your symbols/modules to the kicad
library. For building Kicad from source and other development
questions visit the kicad-devel group at
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