USB is always worse than a PPS directly attached to a serial port. there is far less (orders of magnitude less) uncertainty in the interrupt latency for USB
"Local" is not a good idea. Something called "Orphan Mode" is developed to handle the problem if s disconnected network. If there were a FAQ these tow questions would be near the top of the list Some place else on the list is "Which OS?" I think now Linux is as good as BSD, now that Linux has good PPS support. On Wed, Aug 8, 2012 at 2:34 PM, Rick Jones <[email protected]> wrote: > I've scrounged a couple old Pentium M laptops (Hewlett-Packard nc6000s > for the trivia-minded) with serial ports while entertaining the > possibility of undertaking a project to do what so many others have > done - connect-up a GPS receiver with PPS support. That has me > wondering about some of the previous discussion about USB and how it > is perhaps not "evil" but considered quite sub-par for serving-up the > PPS signal. > > Is that unsuitability inherent in USB, so it matters not whether there > is anything else on the USB, or is it more a case of being "bad" > generally only when other things are on the same USB? I'm still > looking to go serial, but was wondering. > > Also, speaking of things considered "bad" and drifting - fudging the > LOCAL(0) is definitely frowned upon right? If I happen to have say > four servers in a location which might loose its connectivity to the > outside world I probably don't want those servers to fall-back on > LOCAL(0) right? Would configuring each to have the other three as > "peer" entities be the way to go? > > Pointers to the fine manual for any of the above would be welcome. > > thanks, > > rick jones > -- > I don't interest myself in "why." I think more often in terms of > "when," sometimes "where;" always "how much." - Joubert > these opinions are mine, all mine; HP might not want them anyway... :) > feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... > > _______________________________________________ > questions mailing list > [email protected] > http://lists.ntp.org/listinfo/questions > -- Chris Albertson Redondo Beach, California _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
