topic Re: Net classes in design blocks in EAGLE Forum

Net classes in design blocks

grahamUTKMN — Thu, 22 Oct 2020 16:37:11 GMT

I'm really struggling with bringing in design blocks with net classes embedded in them.

Is it true that Eagle ignores the names of the classes and looks at the number 'Nr' on the rules page?

Is there a way to re-order the rule numbers?

What's the best way to work with net classes when bringing them into designs from design blocks?

Thanks,

Re: Net classes in design blocks

jorge_garcia — Tue, 27 Oct 2020 17:12:06 GMT

Hello @grahamUTKMN,

I hope you're doing well. If there's any discrepancy, EAGLE will usually ask you to resolve them, often through an overwrite. There's isn't a nice way to re-order the rule numbers unfortunately.

I'm not 100% sure if EAGLE ignores the names but I know it heavily relies on the numbers so having those setup consistently can make things easier.

In my opinion, the best way to work with classes in designblocks is to not use them. Let all the nets of a design block have default as their netclass. This will address working with the most common scenario which is a few nets need to have a class different from default. Making that change once the block is in the design is simpler than trying to navigate netclass conflicts.

There my be other opinions on this but that's what I would do.

Best Regards,

Re: Net classes in design blocks

grahamUTKMN — Tue, 27 Oct 2020 17:29:24 GMT

Hi Jorge,

Thanks for your reply.

The thing is I'm routing matched differential pairs within the design blocks, so the net class rules makes that much easier.

I ended up with a rule 0 and a rule 2, no rule 1! How can that even be?

Thanks,

Re: Net classes in design blocks

jorge_garcia — Tue, 27 Oct 2020 17:33:43 GMT

Hi @grahamUTKMN,

I'm not sure how that could have been but I'd like to take a look at the files to find out.

I'll DM you my e-mail if you are willing to share the files with me.

Let me know if there's anything else I can do for you.

Best Regards,

Re: Net classes in design blocks

grahamUTKMN — Wed, 28 Oct 2020 09:20:19 GMT

Hi @jorge_garcia ,

I'm afraid the design block doesn't have net classes any longer. To be able to use the design block in a design I had to create the rules to do the routing, then when I wanted to pull the block into my PCB I had to delete the rules, and then re-establish them once in the main PCB design.

So the design block no longer has net classes/rules. It's the only way I could make it work.

Regards,

Graham