On 2011-08-23, Dave Hart <[email protected]> wrote: > On Tue, Aug 23, 2011 at 13:02, Thomas Laus <[email protected]> wrote: >> The capture / assert configuration options does >> not select reading the leading or trailing edge of a PPS pulse, NTP >> only reads timestamps to the on the leading edge and you may require >> an inverter to swap polatity for NetBSD to read and sync to your PPS >> pulse. > > Actually, fudge flag2 does determine whether ntpd refclocks using the > common PPSAPI code (such as the atom/PPS, NMEA, and WWVB drivers) > request timestamps for the assert or clear transition. See > ntp_refclock.c refclock_params(): > > > /* > * Solaris serial ports provide PPS pulse capture only on the > * assert edge. FreeBSD serial ports provide capture on the > * clear edge, while FreeBSD parallel ports provide capture > * on the assert edge. Your mileage may vary. > */ > if (mode & CLK_FLAG2) > ap->pps_params.mode = PPS_TSFMT_TSPEC | PPS_CAPTURECLEAR; > else > ap->pps_params.mode = PPS_TSFMT_TSPEC | PPS_CAPTUREASSERT; > if (time_pps_setparams(ap->handle, &ap->pps_params) < 0) { > msyslog(LOG_ERR, > "refclock_params: time_pps_setparams: %m"); > return (0); > } > > As the comment notes, not all PPSAPI implementations can actually > timestamp either edge. So it's not a limitation of ntpd, but of > NetBSD's timepps.h, in your case.
But from his test, his system is labelling both edges. > > Cheers, > Dave Hart _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
