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Advice on moving forward. (I believe unit's of measurements caused an issue)

StepscanDarcy

I've posted about this a few weeks back, but work has been hectic, and I haven't had a chance to work with ORCAD since.     Here is what's going on.   I have two boards that have  30 pin connectors, which have become obsolete.   We chose a new one, and I got to work making the changes to the board design.   The first board is complete (but being reviewed by someone for me by the company handling the prototype), but when I went to make the changes to the second board, I ran into major issues.   The second board only had one change to make( board #1 had 5).   This change uses the exact 30 pin connector that was changed on board #1.   

When I replaced the footprint on board 1, it simply replaced the old one and broke several connections related to the pins of the connector.   Some simple routing fixed it up in not much time at all (when I figured out what I was doing).   

I was expecting the second board to be done in one afternoon because it required much less work.   To my surprise , replacing the connector on this board, created havoc.  There are ratsnests EVERYWHERE.   So many connections are broken, that it will take me forever to fix it.  

After doing some digging around, I found a possible cause.   Board #1 used one unit of measurement, and board #2 used another(made by different companies), from an old post I found on the forums.   The fix recommended on this thread didn't work for me at all, so now i'm wondering what my next move should be.


Should I just remake the footprint, using the same units as the board?   Or should I change the units of the board to match the units of the footprint?   Is there an even better option that I haven't considered?   Or have I done something else wrong entirely?

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  • Robert Finley

    Make sure connectivity does not change in addition to the footprint.

    Units shouldn't matter as I have footprints in mils, mm, and microns.   

    Try reverting back to the original board and schematic, do a netlist import without changing the connector.  If no ratsnest show up with a re-sync of the original netlist, then change the connector.

  • redwire
    in reply to Robert Finley

    Yep, as Robert says, do a baseline import of the existing schematic to the existing board.  You should get 0 changes.  After that is resolved, the worst case with a change of a 30 pin part is 30 nets to re-route.  There are cases where a component that was built with improper accuracy in one unit system will have rounding errors in the other unit system.  

    Also, make sure that the rip-up copper option is turned off during import of the new netlist...

  • StepscanDarcy
    in reply to redwire

    I'm going to try this today.  Thanks for the help.  I'll post back with my results.

  • StepscanDarcy
    in reply to redwire

    Could you expand on how to do a "baseline import of the existing schematic to the existing board".    I started over from scratch today and ended up with the exact same mess as last time.

    Today, from scratch, I replaced the footprint in the original file, and regenerated the netlist. I still have the same odd DRC errors where they appeared before.

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  • StepscanDarcy
    in reply to redwire

    Could you expand on how to do a "baseline import of the existing schematic to the existing board".    I started over from scratch today and ended up with the exact same mess as last time.

    Today, from scratch, I replaced the footprint in the original file, and regenerated the netlist. I still have the same odd DRC errors where they appeared before.

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