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'Line to Same net spacing' error and disconnects

tmd63

I am trying to work on a design Iand I have a lot of 'Line to Same Net' DRC errors and when I check, the line appears to be disconnected from the pad!

If I slide the 'Cline segs', the cline slides along the rest of the line but stays unconnected to the actual pad it is supposed to be connected to and changes to a rats nest????

  • steve

    Make sure when you route that Snap To Connect Point is enabled in the Options Pane. To resolve these you can also try and run Tools - Derive Connectivity which should make the ratsnest into cline segs.

  • tmd63
    in reply to steve

    Snap to Connect has always been on. This appears to have deleted connections actually on pads after connecting.

    Running derive Connectivity creates more DRC errors.

    Conversion in progress; additional DRC errors found.

    Conversion complete; no errors found.

    Conversion complete; no errors found.

  • excellon1

    In Allegro there are multiple DRC modes that can be enabled / Disabled.

    Suggest you disable "Same Net Spacing" as it is only useful if the physical nets are actually the same type.

    Go to Setup > Constraints > modes to access it.

    Try that out and see how it works for you.

  • tmd63
    in reply to excellon1

    Thank you Excellon1,

    However there is an issue, the design is with a multi-national company AND the checkers replace the rules with a corporate set which would have the 'Same Net Rules' turned on and they would refuse the checking process! This is not a viable option.

    The nets appear disconnected and this is a problem with the design/software and not a DRC issue. The software broke the connections to the pads and then failed to remove the trace, but both the trace and pad are the same net???

  • Wild
    in reply to tmd63

    Slight smile  I feel your pain, I am always fighting others in my design, suggestion that might help.  Once you get you constraints set, export them to a dcf in a personal saved space, and you can reread them back into Allegro anytime you need to?  Sorry, not a fix, but an work around..  ?? maybe

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