8 Replies Latest reply on Jul 17, 2012 6:12 PM by

    Lost Consistency

      Hi,

       

      I wonder if any one provide assistance.  I have lost consistency on my

      board.  I have tried various methods to fix but without success.  I have run

      ERC and identified say this error below:

       

      "Different connections in IC2B pin OE and pad 4 (GND/ none)"

      I interpret this to mean there is a net connection on GND but NOT on pin OE.

      However there is deffinately a net connection in my schematic as I can move

      the GND symbol or my device (74HCT125D) symbol and see that the net is

      connected to both device and ground.

      I have also tried deleting devices and nets and added new devices from

      library, with no success.  I have also deleted nets and renamed there

      another name and still no success.

       

      How can I fix this ?

       

      Many thanks,

      Jim

       

       

       

        • Re: Lost Consistency

          On 3/7/2011 11:36 AM, Jim D wrote:

          Hi,

           

          I wonder if any one provide assistance.  I have lost consistency on my

          board.  I have tried various methods to fix but without success.  I have run

          ERC and identified say this error below:

           

          "Different connections in IC2B pin OE and pad 4 (GND/ none)"

          I interpret this to mean there is a net connection on GND but NOT on pin OE.

          However there is deffinately a net connection in my schematic as I can move

          the GND symbol or my device (74HCT125D) symbol and see that the net is

          connected to both device and ground.

          I have also tried deleting devices and nets and added new devices from

          library, with no success.  I have also deleted nets and renamed there

          another name and still no success.

           

          How can I fix this ?

           

          Many thanks,

          Jim

           

          >

           

          Hi Jim,

           

          This a common issue, especially for new users. What the error is telling

          you is that on your schematic you have the OE pin connected to ground,

          however in the board design no such connection exists.

           

          Here's a procedure for regaining consistency:

           

          To regain consistency run the ERC in the schematic, it will point out

          all of the consistency errors. Do whatever you have to do to correct

          them. If the errors are missing parts in schematic and board, then erase

          the parts from either the schematic or the board that way both are the same.

           

          If there are net issues, again delete or add any traces that may be

          necessary. If you find that the number of net errors is very large then

          you can correct them all by using a netscript.

           

          1. In your schematic go File->Export-> Netscript. Save the Netscript and

          make sure you know where it is.

          2. In your board file turn off all of the layers except 19 Unrouted. You

          should only see your airwires. If you've routed the board you're going

          to have to ripup everything for this method to work. Once you see all of

          your airwires, select them as a group and delete them.

          3. Turn all of your layers back on

          4. Now there's an icon at the top of the screen that looks like a sheet

          of paper with the letters SCR, click it. As an alternative, type Script

          -> Enter in the command line.

          5. Find the netscript we created earlier and run it. You'll see that all

          of the airwires are back. If you run the ERC again, you'll see that all

          of the net errors should be gone.

           

          hth,

          Jorge Garcia

           

            • Re: Lost Consistency

              Am 07.03.2011 19:38, schrieb Jorge Garcia:

              On 3/7/2011 11:36 AM, Jim D wrote:

              >> Hi,

              >>

              >> I wonder if any one provide assistance. I have lost consistency on my

              >> board. I have tried various methods to fix but without success. I have

              >> run

              >> ERC and identified say this error below:

              >>

              >> "Different connections in IC2B pin OE and pad 4 (GND/ none)"

              >> I interpret this to mean there is a net connection on GND but NOT on

              >> pin OE.

              >> However there is deffinately a net connection in my schematic as I can

              >> move

              >> the GND symbol or my device (74HCT125D) symbol and see that the net is

              >> connected to both device and ground.

              >> I have also tried deleting devices and nets and added new devices from

              >> library, with no success. I have also deleted nets and renamed there

              >> another name and still no success.

              >>

              >> How can I fix this ?

              >>

              >> Many thanks,

              >> Jim

              >>

              >>

              >

              Hi Jim,

               

              This a common issue, especially for new users. What the error is telling

              you is that on your schematic you have the OE pin connected to ground,

              however in the board design no such connection exists.

               

              Here's a procedure for regaining consistency:

               

              To regain consistency run the ERC in the schematic, it will point out

              all of the consistency errors. Do whatever you have to do to correct

              them. If the errors are missing parts in schematic and board, then erase

              the parts from either the schematic or the board that way both are the

              same.

               

              If there are net issues, again delete or add any traces that may be

              necessary. If you find that the number of net errors is very large then

              you can correct them all by using a netscript.

               

              1. In your schematic go File->Export-> Netscript. Save the Netscript and

              make sure you know where it is.

              2. In your board file turn off all of the layers except 19 Unrouted. You

              should only see your airwires. If you've routed the board you're going

              to have to ripup everything for this method to work. Once you see all of

              your airwires, select them as a group and delete them.

              3. Turn all of your layers back on

              4. Now there's an icon at the top of the screen that looks like a sheet

              of paper with the letters SCR, click it. As an alternative, type Script

              -> Enter in the command line.

              5. Find the netscript we created earlier and run it. You'll see that all

              of the airwires are back. If you run the ERC again, you'll see that all

              of the net errors should be gone.

               

              hth,

              Jorge Garcia

               

              In addition to Jorge I may add the following: It is perhaps easier for

              you to remove the mentioned IC from the .sch and .brd. Important is that

              you have consistence again before adding more parts.

               

              --

              Mit freundlichen Grüßen / With best regards

               

              Joern Paschedag

               

            • Re: Lost Consistency

              "Jim D" <j.doyle@optosci.com> wrote in message

              news:il31ir$4g5$1@cheetah.cadsoft.de...

              Hi,

               

              I wonder if any one provide assistance.  I have lost consistency on my

              board.  I have tried various methods to fix but without success.  I have

              run ERC and identified say this error below:

               

              "Different connections in IC2B pin OE and pad 4 (GND/ none)"

              I interpret this to mean there is a net connection on GND but NOT on pin

              OE. However there is deffinately a net connection in my schematic as I can

              move the GND symbol or my device (74HCT125D) symbol and see that the net

              is connected to both device and ground.

              I have also tried deleting devices and nets and added new devices from

              library, with no success.  I have also deleted nets and renamed there

              another name and still no success.

               

              How can I fix this ?

               

              Fixing inconsistancy is easy IF you understand it, but its more complex than

              you may think. There is a lot of confusion around on how this works.

               

              First, to resolve a problem, you need to fix the problem AND run ERC again

              to get the design into a resolved state. If you "fix" too much, you end up

              with different inconsistancies.

               

              To fix your problem you need to go to the board and use the "signal"

              command/button and click the pad (hold cltrl while clicking to catch it if

              its outside the grid). The second end of the signal can be either:

              -a loose end (the pin gets a new netname wich you can rename to GND). Click

              on an empty space and left click again to confirm, and esc to end it. You

              will now get an airwire cross on the pad (meaning it has a net, but it

              doesnt go anywere). You can now do the "name" command on it and you will get

              an airwire.

              -a second pad or via from the same signal (unfortunately connecting to a

              wire doesn't work)

               

              Click ERC again to check if it helped.

               

               

               

                • Re: Lost Consistency

                  I now have Consistency in my design, thank you Morten and all for your great

                  input.

                   

                  In the interests of more people having a similar problem, (experienced or

                  inexperienced) here is what I did.  I had tried to fix as directed by Morten

                  below but for some reason I could not get the Airwire Cross to appear on the

                  pad of interest. I could place a signal airwire on the first pad of

                  interest, but when I double click mouse on empty space + press "esc", no

                  Airwire Cross would appear.  I tried this dozens of times with no success.

                  To get round this I tried typing the command directly at the top of the

                  board window using following structure:

                   

                  signal (signal name) (device reference) (pin No) (second device reference)

                  (pin No of second device)

                   

                  eg1 - signal 7RX1+ X5 C9 SV7 3

                  eg2 - signal GND IC1 7 IC2 7

                   

                  Rather than type this for every instance of Consistancy error I used the

                  arrow keys and the previous entered cammand line appeared then I just simply

                  edited this line to suit the next error signal.

                   

                  In the instances where there were tracks already on the PCB but these were

                  also inconsistant, I pressed the "signal" button and clicked on thefirst pad

                  with track still in place.  I then dragged mouse, with Airwire still

                  attached, to second pad and single clicked mouse to attach Airwire.  I then

                  pressed "esc" to release Airwire from mouse.  Next I pressed "ERC" button.

                  Hence, particular error was deleted from error list.

                   

                  Working my way through all errors in this manner resulted in bottom of

                  schematic or board window displaying message

                  "board and schematic are consistent"

                   

                  Many thanks - hope this adds to knowledge base, at least for newbies.

                   

                  "Morten Leikvoll" <mleikvol@yahoo.nospam> wrote in message

                  news:il4o1j$4au$1@cheetah.cadsoft.de...

                  "Jim D" <j.doyle@optosci.com> wrote in message

                  news:il31ir$4g5$1@cheetah.cadsoft.de...

                  >> Hi,

                  >>

                  >> I wonder if any one provide assistance.  I have lost consistency on my

                  >> board.  I have tried various methods to fix but without success.  I have

                  >> run ERC and identified say this error below:

                  >>

                  >> "Different connections in IC2B pin OE and pad 4 (GND/ none)"

                  >> I interpret this to mean there is a net connection on GND but NOT on pin

                  >> OE. However there is deffinately a net connection in my schematic as I

                  >> can move the GND symbol or my device (74HCT125D) symbol and see that the

                  >> net is connected to both device and ground.

                  >> I have also tried deleting devices and nets and added new devices from

                  >> library, with no success.  I have also deleted nets and renamed there

                  >> another name and still no success.

                  >>

                  >> How can I fix this ?

                   

                  Fixing inconsistancy is easy IF you understand it, but its more complex

                  than you may think. There is a lot of confusion around on how this works.

                   

                  First, to resolve a problem, you need to fix the problem AND run ERC again

                  to get the design into a resolved state. If you "fix" too much, you end up

                  with different inconsistancies.

                   

                  To fix your problem you need to go to the board and use the "signal"

                  command/button and click the pad (hold cltrl while clicking to catch it if

                  its outside the grid). The second end of the signal can be either:

                  -a loose end (the pin gets a new netname wich you can rename to GND).

                  Click on an empty space and left click again to confirm, and esc to end

                  it. You will now get an airwire cross on the pad (meaning it has a net,

                  but it doesnt go anywere). You can now do the "name" command on it and you

                  will get an airwire.

                  -a second pad or via from the same signal (unfortunately connecting to a

                  wire doesn't work)

                   

                  Click ERC again to check if it helped.

                   

                   

                   

                   

                   

                • Re: Lost Consistency

                  Hi Jorge,

                   

                  Thanks for getting back to me.

                   

                  Regarding your feedback, I understand your guidance. However, can I provide

                  another example of my Lost Consistency problem, to aid more understanding.

                  I have a 4 pin single inline connector directly connected to a 64 pin

                  backplane connector, (I only tell you this so that you understand it is a

                  simple direct connection).

                  Again no matter if I delete all 4 nets and then add new nets, no matter if I

                  delete 4 pin connector, from schematic and PCB and then add new connector, I

                  get the Consistancy error "Different connections on SV10 pin 1 and pad 1

                  (10RX1+ / none"

                  SV10 = 4 pin connector

                  10RX1+ = net name on pin 1

                   

                  For this connector and with the remaining 3 pins of the connector, I get the

                  same error. This error type is the same or similar for a further 79 error

                  instances in my design.

                  My PCB has been tracked a great deal so deleting all tracks as you

                  previously suggested is not a good option for me.

                   

                  I have checked that there are no such things as missing parts etc between

                  schematic and PCB. Also to point out, there are some devices which have air

                  wires attached to some pins while not being attached to other pins on the

                  same device.

                   

                  Is there another way to achieve consistancy?

                   

                  The option you previuosly stated seems a bit of sledge hammer to crack a

                  nut.  I'm also perplexed as to how this consitancy issue has arose since I

                  always close both PCB and Schematic by closing Control Panel, and I never

                  work with either the schematic or board open individually - they are always

                  open as a pair and closed as a pair.

                   

                  Anyway I hope this provides a greater picture as to my problem, hope you can

                  help.

                   

                  Many thanks.

                   

                  Jim

                  "Jim D" <j.doyle@optosci.com> wrote in message

                  news:il31ir$4g5$1@cheetah.cadsoft.de...

                  Hi,

                   

                  I wonder if any one provide assistance.  I have lost consistency on my

                  board.  I have tried various methods to fix but without success.  I have

                  run ERC and identified say this error below:

                   

                  "Different connections in IC2B pin OE and pad 4 (GND/ none)"

                  I interpret this to mean there is a net connection on GND but NOT on pin

                  OE. However there is deffinately a net connection in my schematic as I can

                  move the GND symbol or my device (74HCT125D) symbol and see that the net

                  is connected to both device and ground.

                  I have also tried deleting devices and nets and added new devices from

                  library, with no success.  I have also deleted nets and renamed there

                  another name and still no success.

                   

                  How can I fix this ?

                   

                  Many thanks,

                  Jim

                   

                   

                   

                   

                    • Re: Lost Consistency

                      "Jim D" <j.doyle@optosci.com> wrote in message

                      news:il4vih$fdo$1@cheetah.cadsoft.de...

                      Is there another way to achieve consistancy?

                       

                      The simplest way is to delete all nets to the conflicting pins both in sch

                      and brd. In sch its easy.

                       

                      In brd you need to get an airwire to the pin only before you delete it.

                      -If there is a wire going to the pad, start by deleting that.

                      -Do ratsnest

                      -Llook for an airwire. Make sure there is just ONE airwire going to the pad.

                      If you get two, you will have more problems after deleting them because you

                      will split a net into two different net names. To fix that, do a temporary

                      route around the pin (doesnt matter if you overlap) and do ratsnest again.

                      Note, if the pin is surrounded by filled polygons, you should temporary

                      rename the polygon to something else and redo ratsnest.

                      -When you got one airwire to the pad, delete THE AIRWIRE.

                      -Redo temporary changes 

                      -Now try ERC again.

                       

                       

                       

                        • Re: Lost Consistency

                          On 03/08/2011 01:12 PM, Morten Leikvoll wrote:

                          "Jim D" <j.doyle@optosci.com> wrote in message

                          news:il4vih$fdo$1@cheetah.cadsoft.de...

                          >> Is there another way to achieve consistancy?

                           

                          The simplest way is to delete all nets to the conflicting pins both in sch

                          and brd. In sch its easy.

                           

                          In brd you need to get an airwire to the pin only before you delete it.

                          -If there is a wire going to the pad, start by deleting that.

                          -Do ratsnest

                          -Llook for an airwire. Make sure there is just ONE airwire going to the pad.

                          If you get two, you will have more problems after deleting them because you

                          will split a net into two different net names. To fix that, do a temporary

                          route around the pin (doesnt matter if you overlap) and do ratsnest again.

                          Note, if the pin is surrounded by filled polygons, you should temporary

                          rename the polygon to something else and redo ratsnest.

                          -When you got one airwire to the pad, delete THE AIRWIRE.

                          -Redo temporary changes 

                          -Now try ERC again.

                           

                           

                           

                          After removing erroneous nets, you must run ERC again for the brd and

                          sch to become consistent again BEFORE you reconnect what once was

                          removed. As long as there is an inconsistency noting you do in sch will

                          end up in brd.

                           

                          1) Remove

                          2) ERC

                          3) Repeat 1) and 2) until consistency has been achieved

                          4) Add what was once removed.

                          5) Celebrate

                           

                          Breg

                          Vidar(Z)

                           

                      • Re: Lost Consistency

                        I have a problem similar to Jim Doyle's, but with a twist. I've begun a

                        board revision which includes replacing a few parts with different types

                        and correcting a couple library parts. These were 2 connectors, same type,

                        4- and 5-pin versions. In the first edition of the board, we got the order

                        of the pins reversed from what the customer wanted, so I edited the library

                        parts to reverse the pin order (1=>5, 2=>4, ...). when I did the update

                        library on the board, the 4-pin switched correctly, making the connections

                        correctly, but the 5-pin kept the connections in the same physical

                        location, i.e., now connecting to the wrong pins (except pin 3, of course).

                        It looks like I need to do something like Doyle did to remove those

                        inconsistencies. What do you think happened here?

                        --

                        Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.