> Yep, that's to be expected, given the iterative solver they're using. > Try turning on the ZDA message, apparently the $ sign is aligned to > the start of the second ... if its implemented in your version of > firmware. Since you're running a BU-353 you could have all kinds of > broken things in your firmware (not impressed by Globalsat).
Do you expect the ZDA message to be better synchronized than any of the others? Is the BU-353 any better or worse than any of the other units using the SiRF chips? I've tried several different brands. I can't tell them apart unless I look at the physical package. > As an aside, how and what are you collecting? I'm starting to think > about setting up different loggers to catch the leap second... I just plug them into ntpd, use the noselect option on the server line, and turn on ntpd's statistics. > I've used the LVC w/ PPS as the reference clock... not sure that I > trust the delay/jitter characteristics of USB enough to give me better > time than a wrist-watch. USB isn't fundamentally evil. It's polled, so you won't get great response to something like a PPS interrupt. But the polling is handled automagically with modern hardware so It's not much worse (maybe better) than the typically interrupt batching that RS-232 chips do. I think USB will be good enough if your target is a few milliseconds rather than a few microseconds. -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
