Greetings

I would like to put my dido on what Mr. DeGenova has said below and
add that if you are out of sink it also creates problems doing ECO's
View Draw to Power PCB. The rule here At I-O Corp. Is once I start
the layout they are not to touch the schematic. Back annotation of
gate swaps is possible if done in a certain way. The symbols in View
Draw must use the HETERO attribute in a very specific way.

Lay down the law. No messing with the schematic until the back
annotation of the ref des is complete and they have a prototype board
in hand.

good luck

Walter L. Williams
Sr. Circuit Board Designer
I-O Corporation, Industry leader in AS400 connectivity products
[log in to unmask]


> Derek,
>
> One thing I have found to be an absolute necessity is to freeze a copy of
> the schematic after generating the Pads netlist until you are ready for back
> annotation from Pads or need to forward annotate schematic changes while
> layout is in process.  What I have found to happen is that while the board
> is in layout, the engineer makes changes to the schematic.  If both the Pads
> and Viewlogic netlists have changed, automatic synchronization may become
> nearly impossible.  Only change one netlist at a time (either Pads or
> Viewlogic), then synchronize the two before any other changes are made.
>
> We have also found that it is cleaner to make netlist changes in viewlogic
> and forward annotate them to Pads, as opposed to using the Pads ECO
> functions to change any connections.  We limit Pads netlist changes to
> resequencing of the reference designators.  It also helps to have one person
> who understands both programs in control of the Viewlogic schematic and the
> Pads layout if possible.  If the two are controlled by different
> individuals, both must understand how their changes affect the other program
> and keep clear communication throughout the development cycle.
>
> Jon DeGenova
> Micro Industries
>

> > Hi Folks,=20
> >
> > We are having nightmarish problems controlling Eco's while using
> > Viewdraw and PAD's.=20
> > The process is so open to disastrous error by the operator that it has
> > cost us significant=20
> > amounts of time back-tracking to recover files and data. Has anyone =
> > else
> > had experience of the=20
> > interface between these tools and if so what procedures did you use to
> > control the process.=20
>>
> > Thanks in advance.=20
> >
> > Derek=20

> > Derek J. Wynne=20
> > Design Engineer.=20
> > Toucan Technology Ltd.=20
> > I.D.A. Business Park=20
> > Dangan=20
> > Galway City=20
> > Ireland.=20
> >  =20
> > Telephone: +35391519913=20
> > Fax:          +35391519901=20
> > E-mail:       [log in to unmask] < mailto:[log in to unmask]>=20
> >  =20

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