5 Replies Latest reply on Feb 17, 2014 4:33 AM by brad.achille

    Connected Routes that show as unconnected

    Adam.Bierman

      Hi All,

       

      I am working on a design and I am running across unroutes that don't make sense and am hoping someone has an idea how to resolve them.  I have multiple power voltages running across my board and a few of them are showing up as unconnected when they are connected to the power layer through a via.  I've attached a screenshot of one of the examples of this.  Is there a reason that these connections are showing as not connected, and what can I do to resolve this?

      unroute example.png

        • 1. Re: Connected Routes that show as unconnected
          jduquette

          PADS has a little quirk that a trace can go under a pad and look like a vaild connection, but if it isn't routed all the way to the center of the pad it still gets counted as disconnected.  You probably have that on one of the pads that the line is drawn between.

           

          Select a pad and start routing.  You may only have to move your cursor 0.1mm until you'll see the cursor change to the connect symbol.  If it doesn't work at one end, try the other end.

          • 2. Re: Connected Routes that show as unconnected
            wolferm

            Anoher way, if you have quite a number of places a net goes to, is to turn everthing to black except conections.

            You will quickly see the dot of a connection line.

            Also if a power connection, an dyou have a number of layers or planes for say gnd

            When you do a design verify under planes use setup and uncheck "same layer connectivity"

            this can also give you false verification.

            • 3. Re: Connected Routes that show as unconnected
              Adam.Bierman

              Thanks everyone for your replies, I still can't seem to get some of my connections to behave correctly, and I am not getting the connect icon on these particular points.  Is there anything in PADS that will automatically snap my vias or routes to the correct location?

              • 4. Re: Connected Routes that show as unconnected
                David Ricketts

                I know it sounds wrong, but the display of the connection lines don't always mean there's no connectivity. It sometimes just shows that the routing doesn't match the topology setting. You can use View/Nets to control the display for both default and specific nets. To track down the actual errors. run Verify Design for Connectivity, and use that report.

                 

                Regarding your picture: Using outline mode can sometimes reveal hidden errors. But from what I can determine on the far right side, and if the red and salmon colors are different layers, there's a via missing at the top of the fat vertical salmon trace where it meets the skinny red trace, indicated by the diamond tack marker.

                • 5. Re: Connected Routes that show as unconnected
                  brad.achille

                  This may not apply to your particular issue, but I have noticed that sometimes I see those unconnected ratsnest lines if there is a small floating trace buried within a pad. I will turn on the outline mode (O) and try to find it. Though there are times when it just flat out does not make sense why there is an unconnected line.