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Re: Eeschema ERC should detect unmatched local labels

 

@Wayne and @JP,

Could try ERC on this simple schematic file?

Attached, you can find a test schematic file that has an unintended unmatched local labels, and current kicad ERC does not detect them.

In the test schematic file, there is a mis-spelled local label on the right hand side. The local labels are constructed with an intention of using them to serve as ratnets, not just a convenient text. With this kind of mis-detected errors, the PCB will not have the intended ratnet at all and thus no copper track will be laid out, and thus the manufactured boards will be bad.

--Joe

On 09/13/2015 01:00 PM, Wayne Stambaugh wrote:
On 9/13/2015 2:45 PM, jp charras wrote:
Le 13/09/2015 20:11, Wayne Stambaugh a écrit :
On 9/13/2015 1:50 AM, Lorenzo Marcantonio wrote:
On Sat, Sep 12, 2015 at 10:49:59PM -0600, Joseph Chen wrote:

Though you don't approve the change now, I hope you would approve it
sometime later soon, like maybe RC2. I am saying this because I
believe the fix is crucial for KiCAD to be improved towards a
production quality EDA, after I encountered my PCB's near "DEATH"
situation.
I don't think that checking unmatched names is so critical. In fact
*most* of my labels are simply used to... label nets, not to create a
connection. That way during routing I can see the signal which need
particular attention (also it's easier to set netclasses in this way)

A distraction like a mistyped label is akin to connecting a wire to the
wrong pin (one time I flipped over an amp symbol... lot's of smoke
happened :D); no ERC can save you from that.

The *only* feature useful in the schematic DRC is the 'unconnected pin'
warning; all the other ones (signal conflicts, power pins and so on) are
a complete nuisance (at least for mixed signal and analog-heavy boards).
Even for digital boards a filter inductor on a power pin would give a
missing power warning :P

When a pin is connected to a wire with a label that doesn't go anywhere,
does the ERC generate an error?  It probably should because technically
this is still an unconnected pin.  This is a more sensible then checking
for unmatched label names for the reasons Lorenzo stated above.

Yes, because unconnected pins without no connect symbol are detected.


Then this should be adequate to detect the problem as it was described
or we have a bug in the ERC code.  @Joseph, did you get an ERC error
with your mismatched labels.  If so, then the ERC did it's job properly.
  I don't think your changes make any improvement and in some cases will
cause issues with net labels.


Attachment: kicad-unmatched-local-labels-schematic.tar
Description: Unix tar archive


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