Fabrizio, I have a couple of points you should be aware of. 1. You do not HAVE to tie all of the ground nodes set to zero, but if you don't be prepared to accurately model your interconnect, connectors, decoupling and signal to return ratio's. 2. When you are displaying an Eye pattern on a remote board not tied to zero, use the remote reference for your signals reference. 3. If you are using a connector model that contains partial inductances you will violate the assumptions of the field solver used to create that model if you ground (tie to zero) both sides of the connector. Regards, Bob Robert J. Haller (rhaller@xxxxxxxxxx) Principal Consultant Signal Integrity Software Inc. 6 Clock Tower Place, Suite 250 Maynard, MA 01754 Phone: (978) 461-0449, ext 15 Fabrizio Zanella wrote: >I have a question regarding backplane simulations of serial 8b/10b >signals, running 2.5Gbs and above. Does it matter whether the ground >nodes of the daughtercards and backplane are all set to 'zero' or to a >floating node for eye pattern results? >Thanks, > >Fabrizio Zanella >Principal Hardware Design Engineer >Broadbus Technologies >fzanella@xxxxxxxxxxxx > > ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu