Hello,
I have a suggestion that could help us when we route kelvin connections or when we have to connect 2 separates ground planes in only one point ("star" connection). For example when we had to connect two ground GND-logic and GND_ANALOG in one point only under the ADC....
For this kind of situation, even if all connexions must be connected together, some of them play different roles and could have different parameters (minimum width for kelvin connection).
Today I only found 2 ways for doing this:
1) On a schematic side, I use one single net (same name). With this approach, on the board side, Eagle consider that all must be electrically connected. That is gread for DRC, but I have to manually check that the separation is correctly done, and some time I must add cutoff polygon (specially for GND planes). I also have no possibility to define different min width (same net = same class), ....
2) Or I use 2 different nets, and a "kelvin connection part" that I have build in my library. Finally Eagle consider the 2 sides of this component as 2 different nets. Great, BUT, DRC is not really happy when I connect, the 2 nets with a manually added copper polygon or wire.
That I'm suggesting is:
I think that the best approach is to consider that we used different nets (different names) that we connect together with one special component. In schematic, these nets are totally independent (as in my solution 2). In broad, the package associated to this component would be a special package, that we can placed and locked like the other packages. But this package will take the form of a polygon (or at least a rectangle), We simply place this polygon (or rectangle) exactly where we want the connection of these 2 nets. This special polygon, will simple indicate to EAGLE (DRC and auto-router) that in this area and in this area only, these 2 nets must be proceed as only one net. The polygon let us decide the form of the connection.
In this way, it's easy to separate the 2 signals in schematic and in board. In the board we can decide where and how the connection is made. The DRC don't report any stupids error. And the DRC check the separation (isolate, with,...) of the to net, except under our special component.
Guillaume Barrey
