Change layer issue

On 8/19/2016 8:01 AM, Morten Leikvoll wrote:

Maybe this issue is related to the topic "grabbing airwires on routing"

just below, cause the intelligence about wire endpoints seems to fail.

 

Look at attached image. Group the green wires, also the one under the

red wire, but not the red one. Change layer (to any layer). Eagle now

inserts a via where there shouldnt be one.

 

 

 

Hi Morten,

If if you include the route command in the operation it might add in the

via as part of a routing operation.

I don't clearly see the issue in the picture you have attached, the top

trace needs the via in order to connect to the trace on layer 11 right?

Sorry if I'm a little dense, but could you clarify the issue more?

Thanks Morten.

Best Regards,

Jorge Garcia

On 19.08.2016 22:39, Jorge Garcia wrote:

On 8/19/2016 8:01 AM, Morten Leikvoll wrote:

Maybe this issue is related to the topic "grabbing airwires on routing"

just below, cause the intelligence about wire endpoints seems to fail.

 

Look at attached image. Group the green wires, also the one under the

red wire, but not the red one. Change layer (to any layer). Eagle now

inserts a via where there shouldnt be one.

 

 

 

Hi Morten,

 

If if you include the route command in the operation it might add in the

via as part of a routing operation.

Ok, I probably didnt make myself clear enough. To proove my point,

seeing is believing. Try this on the attached board file:

display none 11 via;

group all;

display last;

change layer 10 (>c0 0);

Now, what in the world could justify adding those vias there, when its

already perfectly connected without them?

On 08/22/2016 03:32 AM, Morten Leikvoll wrote:

On 19.08.2016 22:39, Jorge Garcia wrote:

On 8/19/2016 8:01 AM, Morten Leikvoll wrote:

Maybe this issue is related to the topic "grabbing airwires on routing"

just below, cause the intelligence about wire endpoints seems to fail.

 

Look at attached image. Group the green wires, also the one under the

red wire, but not the red one. Change layer (to any layer). Eagle now

inserts a via where there shouldnt be one.

 

 

 

Hi Morten,

 

If if you include the route command in the operation it might add in the

via as part of a routing operation.

 

Ok, I probably didnt make myself clear enough. To proove my point,

seeing is believing. Try this on the attached board file:

 

display none 11 via;

group all;

display last;

change layer 10 (>c0 0);

 

Now, what in the world could justify adding those vias there, when its

already perfectly connected without them?

 

Interesting...

I believe I see what's happening.  The group has a collection of wires

and vias in it.  When the "change layer" is applied to the entire group,

Eagle iterates through the group, performing that operation on every

element.

I tried "change layer 10" and sequentially selecting each element in the

group, starting with the wire on the far left.

Just for brevity: in the images that follow, red is on layer 1, green is

on layer 11, and hashed blue is on layer 10.

First click:  The left wire changed to layer 11 and left a via at the

right end connecting to the first diagonal on layer 10.

Second click: The first diagonal change to layer 11 and removed the via

that was created on the first click.

Third click:  Being careful to NOT select the wire on layer 1, the

second diagonal changed to layer 11 and left a via on the top right end

connecting to the next segment on layer 11.

So at this point, there's a new via that connects layers 10 and 1 to the

bottom left, layer 1 to the top right, and later 11 to the right.  This

must be added to keep these the next segment connected.  It turns out

that the additional via connects not only 10 and 11, but also 1.

Fourth click: This is on the horizontal wire in the center.  It moves to

layer 10, but leaves the via on the left end because it also connects to

layer 1.  i.e. the operation does leave a via connected on only one layer.

Now... If I undo everything and add a buried via between 10 and 11 to

the DRC Layers setup:

and run through the same exercise again (I'll skip the first two clicks)...

Click 3 on the second diagonal gets a buried via on the top right:

Click 4 on the center horizontal: This does what you expect.  The buried

via is removed because only one layer was connected to it after the wire

changed to 10.

I believe that Eagle is doing what it's supposed to do, however, it has

no knowledge of what previous iterations of an operation on a group did,

and assumes that the problem via was added by the designer and thus

needs to stay there.

Does this help at all?

    - Chuck

Now, what in the world could justify adding those vias there, when its

already perfectly connected without them?

 

Hi Morten,

I can confirm the behaviour. I think Chuck's analysis of the situation

is likely correct, however the end result is still undesirable.

For this reason I have filed a report with the devs to investigate the

issue.

hth,

Jorge Garcia