> Le 10 déc. 2014 à 19:55, Laszlo Hanyecz <las...@heliacal.net> a écrit : > > Time-nuts, > > Is it a bad idea to have more than one PPS source on a single machine? Would > this cause additional jitter when trying to compare the timestamps on two > sources? I understand that USB can't deliver a real PPS, but what about > using onboard serial ports or a PCI card? >
You would have to test I guess but the potential is there for an issue. It can be circumvented by configuring a 1PPS offset if the receiver allows it , or configuring a reasonable cable delay in the receiver so that the pulses are not simultaneous . The latter possibility exists for the Venus 8 receiver , but I cannot find a command to force a 1PPS offset. > Thanks, > Laszlo > > > -----Original Message----- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Paul > Sent: Wednesday, December 10, 2014 18:43 > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] 10MHz LTE-Lite - PPS accuracy? > > On Wed, Dec 10, 2014 at 12:17 PM, <gign...@gmail.com> wrote: > >> Quite simply - if you either execute ldattach pps /dev/ttyUSBx, or are >> running GPSD (recommended) it will bind the USB appropriately to a >> ppsapi instance. >> > > I can get a /dev/ppsN but ppstest says time-out. I saw some hints that the > USB DCD > > might depend on the chipset . I don't like gpsd so I try to avoid it but I > might try it. > > Thanks. > >> Do not do it. You will not approve of the results. >> > > I don't intend to use it in production. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
