Re: What is your favourite PCB software?

In article <36270c91-22f2-4be2-8324-5d613ab1d0a1
@a23g2000hsc.googlegroups.com>, rickman says...
On Apr 20, 9:53 pm, Robert Adsett <s...@xxxxxxxxxxxxxxxxxxxxx> wrote:
In article <2c0987d9-e17d-4797-9adf-4960fd3f3b6b@
8g2000hse.googlegroups.com>, rickman says...

On Apr 10, 9:49 pm, James Morrison <sp...@xxxxxxxxxxxxxxxxxxx> wrote:
The real reason I like it is that the schematic and PCB are coming from the
same database (other s/w has this to, PCB123 from Sunstone is one example).
Thus there is no forward or back annotation--all modifications are applied
to both simultaneously. This is a big bonus and seriously cuts down on
chaos when things change.

Is it an open database? Can I write tools to pull data out of it and
to update it without using Eagle? For example, if I design in a part
and in procurement the part is substituted, do I have to go into Eagle
to make the change or can I change the database externally?

I don't follow Rick. If the part is form and function compatible then
there is no need to update the PCB or schematic. If they are not then
you need to go into the programs to changes the schematic and/or PCB.
Surely you're not thinking of keeping approved source in the
PCB/Schematic? (I know people who object to keeping resistor values in
the schematic, preferring to keep them separately for configuration
flexibility)

I put part numbers in my schematic. I then generate a BOM from the
schematic using those part numbers. I don't have any sort of data
base to track component changes, so I update the schematic when I
change components. Not including resistor values would certainly make
reading a schematic difficult without the lookup table for the
values.

It has occurred to me that this is a good reason to use company part
numbers. A company part number can be equated to multiple qualified
parts for that socket. But this is another level of complexity that I
am not currently prepared to support.

I'd bet you don't put resistor part numbers on your schematic (just
resistance values) so you are already part way there :)

And how do you deal with variant stuffing?

Seriously, if you are producing more than one or two boards just for
yourself you need to do this, it'll keep you sane as part supplies vary.
Part specs can be as simple as listing approved manufacturers and their
associated part number up to a full set of critical to quality
parameters to make it easier for a contract manufacturer to suggest
alternates. Something like Parts and Vendors helps a lot with the
first.

There are still plenty of situations where I would want to edit the
parts information in the schematic like it was a spread *** or
externally update it. Orcad actually provides this capability and
would only be better if they did a more complete job of it.

It doesn't even matter if you agree with my example. The point is
that open formats are better for many reasons.

That I won't disagree with.

I don't want to work
with closes proprietary design files anymore and I won't. For my next
design I will not use Orcad any more and I won't be using Eagle if
their file formats are closed.

For myself, I find copy protection far more disagreeable and potential
dangerous. Eagle does have that drawback as well even if it is one of
the lighter forms. Eagle does have provision for getting at their
database programmatically and writing it out so it's not fully closed.

OTOH, I wouldn't want to give up the tight coupling between schematic
capture and layout that Eagle provides. It's not impossible to get the
schematic and PCB out of sync but you have to work at it a bit.

The last time I checked the open alternatives they were pretty much in
their infancy, little coupling between PCB and layout, and difficult to
install.

Robert
** Posted from http://www.teranews.com **
.