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OrCAD Layout problems with airwires/net connectivity

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cosmicboy

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Hi folks,

I am having some interesting 'net' problems in Layout, which I can't seem to resolve.

Ever since I started using Layout I would get some strange acting airwires, which wouldn't go away even though there was solid copper connection between two points, and I always thought that was due to grid settings so I ignored most of them. I must admit I haven't done any research on this or asked anyone but today I feel like I've had enough and this one net in my current design has been driving me up the walls so here's my question: Are there any tips/tricks to clean up redundant airwires?

What do I mean by 'redundant airwires'? Let me demonstrate:

(click to enlarge screenshots)

The first one is quite simple:
**broken link removed**
Via 'A' clearly has copper connection to pad 'B' (as highlighted by the cyan track I drew), yet the airwire is still there after hitting 'Refresh All' multiple times.

Second one:
**broken link removed**
Pad 'B' is connected to Pad 'C', which is also connected to Pad 'A' (as demonstradted by the cyan track) yet there is still an airwire between Pad 'A' and Pad 'C'

Third and the most irritating one:
**broken link removed**
Pad 'A' and Pad 'B' needs to be connected, so in an effort to do that I bring Track 'C' close to the Track 'D' but the connection won't 'stick' (not sure what the exact term for this is, but you kow when you start routing a track and once you hit the destination the track is 'stuck', i.e: it's deselected). I've tried pretty much everything, including removing Track 'D' etc. but no matter what I do the airwire between Pad 'A' and Pad 'B' won't dissapear! The reason this happens, I think, is the via next to Pad 'A' doesn't seem to be connected to the pad itself (if you look closely you can see the airwire), but that again won't dissapear no matter what I do.

Apologies for the long post, but this is really starting to get on my nerves. I might be doing a total beginner mistake, as I learned Layout pretty much by trial and error (and because of the lack of practical session at university, but that's another topic) so any comments/suggestions on this will be very much appreciated.


Regards.
 

I think your fist and second problem is becuase of Grid settings ( rotuing/via /place grid) are not matching.
You try this .delete the segment (do not delete via) that entering to via then using "finish" command (right click-->finish or press F) complete the routing of prticular net.
I believe there will generetae a new via and airwire (unrouted net?) will disappear.
Third issue seems strange .i think you are trying to violate some DRC rules. Try to route the net with DRC off (eventhouh it is not recommended)
 

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