[solved] diff pair headaches

[aandrew]

Hey everyone,

I'm not new to Altium, nor to using differential pairs in Altium, but I cannot resolve this compile error regarding diff pairs.

The circuit:



I have USB_D_P and _M (and FTDI_D_P/M). I've got the pair clearly marked with a diffpair directive, and hovering over the wire shows the wire is picking up the net name. The compiler, however, flags two related errors:

1. "Missing Negative Net for differential pair [USB_D], positive net [USB_D_P]", and
2. "Missing Negative Net for differential pair [USB_D_M], positive net [USB_D_M]"

?! It thinks that my USB_D_M is the positive net for a brand new pair, not the negative net for the USB_D pair! It's also complaining about that for FTDI_D and FTDI_D_M, but that's just the same issue with another diff pair.

I have two dozen other diff pairs on other schematic sheets without this problem.

I've tried adding diffpair directives on the nets at the USB connector J7, I've tried renaming the nets so there is only one underscore (for _P and _M), I've tried nuking the net names/directives and adding them back... this is maddening!

[ajb]

The suffix for the negative side of the pair should be _N

FYI, you can use a single diffpair directive attached to the blanket to set the diffpair property as well as the class.

[aandrew]

 

Thank you. I did not even see that. Of course it works now. I'm an idiot.