My 2 Cents; My obversations;
I sat in on a committee of the IPC-D-356 sometime  back in 92'.
IPC was trying to understand the problems, having set up CAD systems
and Manufacturing teams to transfer data to manufactures from the various
systems..
Results in a nut shell..The problems are the users lack of consisency
in the way thay do things. One problem being test coupons, nobody
does them the same way. 
OK..do you get it ..everybody does different work arounds, and when this data
comes out the standard didn't expect it that way.
So as long as users all call things differently and do different
work arounds they will be infective data transfer, IPC-D-356
one example.  So we have meet the emeny and he is us !!!

My OPINION on EDIF is different it will become the defacto netlist standard!!
Why..because too many be players are pushing it and it's the standard data
format for VHDL  and transfer to simulators.  

Lou Dallara

>From "Pete Waddell" <[log in to unmask]>
> 
>      Ross is absolutely correct when he says that we will continue to have
>      problems in the future. In my mind (purely my OPINION) 5the only thing
>      that will bring D-35X into common use would be a compelling reason
>      from users. I am finally convinced that there is not an EDA conspiracy
>      to kill D-350. The EDA developers will support something when the
>      users demand it. Untill users have a compelling reason to use a
>      format/standard there is no reason to support it. All fabricators and
>      manufacturers DO NOT support D-350. The few that do and have offered
>      discounts on tooling for D-350 have not done enough to make the user
>      community aware of this. It has been a very haphazard effort.
>      Gerber became a "standard" because board shops promoted the cost and
>      time advantages (to the customer) of Gerber files, and because they
>      (board shops) began to demand files over films.
>      Gary is absolutly right when he states that EDIF is not adequate for
>      manufacturing - at this point. EDIF 4 0 0 contains electrical and
>      component data but is weak in manufaturing data. I've heard that the
>      IPC and EDIF are trying to work together to establish a data format,
>      but with all due respect to Gary the IPC and the volunteer committees,
>      volunteer committees by their very nature take an inordinate amount of
>      time to get things going. The true answer (again my opinion) is one
>      that will involve pain and dedication from the user community - but
>      that's a topic for other venues.
> 
>      Pete Waddell
> 
> 
> ______________________________ Reply Separator _________________________________
> 
> Subject: DES- Gerber formats?
> Author:  [log in to unmask] at Internet
> Date:    11/4/96 8:02 PM
> 
> 
> On  4 Nov 96 at 12:33, Gary Ferrari wrote:
> 
>  >Ross La Gue,
>  >
>  >I would like to comment on a couple of issues you make. First, all
>  >of the bare board electrical test manufacturers support IPC-D-356.
>  >As a matter of fact, they are the ones that wrote to specification,
>  >and are responsible to keep it current. There are no plans, nor a
>  >desire to support a standard such as EDIF, since it does not support
>  >the manufacture of bare boards. What little support it has is
>  >inadequate.
>  >
> 
> 
>  My original comment to the Technet forum was that I didn't expect
> a groundswell of support for IPC-D-356. None of the PC based CAD
> packages I have used support it.  Most have EDIF support.  Also, I
> originally commented that the netlist problem was a big problem.
> That comment was made in the context of a discussion on SMT pads
> drawn with RS-274-X macros.
>  In order to solve this problem we require the cooperation of the
> EDA industry as well as the board manufacturers and testers. I'm
> sorry if my reply isn't politically correct enough for you, but
> the IPC standard isn't worth a hill of beans if we all can't agree
> to use it.
>  If the bare board electrical test manufacturers are not willing
> to support EDIF and the EDA vendors are not willing to pay to support
> IPC-D-356, then we will still be having a big problem in the future.
> in fact, if I recall, this same discussion several years ago in
> the pages of _Printed Circuit Design_ mag.
> 
> ---
> Ross LaGue          < [log in to unmask] >          Dayton, Ohio
> 

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