ERC finds not connected pin which is connected


The situation: I have a hex inverter in one Subsheet, the output of four modules is connected to hierarchical output labell.
On an other subseet, there is an adder with four input pins connected to hierarchical input labels. The inverter outputs are connected to these adder inputs, but the ERC gives a “Pin not connected” error on two of the adder inputs. Any suggestions? the pins do look connected (no small squares on the end)


The ERC is not likely to be wrong.

Delete the last segment of each “wire” to these connections.

Change your grid to 50mills and move the part.

Re-“wire” to the new grid spacing.


I see irregular spacing on your Z labels.
EEschem does not snap (yet?) to pins as PCBnew does to pads and is fussy about coordinates, they have to match exactly, and the easiest way to do that is to draw everything on a 100mil grid.

Have you changed your grid during this design?
what happens if you drag (with “g”) a schematic symbol? Do the wires stay attached?
(Press ESC to cancel the drag and return the symbol to it’s original position when done)


I rewired the part in question in 50 mill Grid (100 does not work, as the inverter pins don’t align to it).
Still the same Result.
When I drag the components, the wires stay attached, also the “Highlight net” Feature lights up the whole wire between the parts.


Could you post the error messages from the ERC dialog?


It could be that the part has those pins off of the 50mill grid. You may have to “fix” the symbol.


Sorry, I was away a few days.
The pins in question are all on the grid, and cleary shown as connected by Eeschema.

I get a combination of both ErrType(2) and ErrType(3), together more than 600, so there seems to be a systematic error in my schematic.

On the other hand, I just created a netlist and looked for one of the pins in question. In the Netlist it is connected to the right output, so the ERC seems to be confused by something?

If anyone wants to look into the schematic, you can find it here: (beware: ugly)


What kicad version did you use?
I get an error message in kicad 4.0.6 that you used a newer version.
I would guess you use a nightly build version from before the merger of the symbol lib table stuff. (so before november last year)
There might just be a bug in that version.


I installed it a few weeks ago.

Version: 5.0.0-rc2-dev-unknown-904eb82~65~ubuntu17.10.1, release build


Strange i could open it in 4.0.6 (I just assumed that 4.0.6 can not open any schematic produced by such a late nightly build.)

Granted i got error messages but that is kind of good news for everyone.

Now back to the topic at hand. I investigated your project a bit. I really have no idea why it does not work. It is a very large project and kicad struggles quite a bit with every operation that requires parsing all files. The hierarchy is also quite deep in places.

Definitely strange is that the first ERC message i get states that U246 has unconnected pins. If i click on it, kicad however puts me into the hierarchical sheet containing U25.

When i search the project kicad does not find U246 so it seems you somehow damaged the information about what hierarchical sheet contains what part. Or maybe more likely, kicad has a problem with such complex hierarchies. I suggest you head over to the bugtracker and report this as a possible bug. (If you do, link to that bug report from here and link this discussion in the bugreport.)
For anybody else who is curious, U246 is found in /PC/PCInc/PCInc8
U25 however is in /ALU/SUB_INC


Yes, you’re right: the schematic is a complete mess! :wink:
I have tried to follow some nets. They are apparently right, but I still get a non-connection warning.

Many false connections like Y2 (left side of the picture). Try to draw the whole schematic with clean nets and labels. Hierarchical labels have an orientation option, so they can point to the direction you want without being crossed by wires. Good luck!