Date: Thu, 16 Dec 1999 13:53:11 -0700 From: Warner Losh <imp@village.org> To: nate@mt.sri.com (Nate Williams) Cc: "FreeBSD Current Users' list" <freebsd-current@FreeBSD.ORG> Subject: Re: HEADSUP: ntp4 to replace xntpd Message-ID: <199912162053.NAA74078@harmony.village.org> In-Reply-To: Your message of "Thu, 16 Dec 1999 13:48:08 MST." <199912162048.NAA21039@mt.sri.com> References: <199912162048.NAA21039@mt.sri.com> <199912162043.NAA20958@mt.sri.com> <199912162035.NAA20788@mt.sri.com> <199912161810.LAA19919@mt.sri.com> <Pine.BSF.4.05.9912160934230.23583-100000@semuta.feral.com> <16818.945366687@critter.freebsd.dk> <199912162032.NAA73759@harmony.village.org> <199912162041.NAA73896@harmony.village.org> <199912162046.NAA74003@harmony.village.org>
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In message <199912162048.NAA21039@mt.sri.com> Nate Williams writes: : > : Cool. I was under the impression that the cheap NMEA signals only gave : > : 2-5sec accuracy given the 2400 baud speed issues. : > : > If you have a PPS signal, then you can get fairly close even if the : > inforation about the PPS signal comes in at 2400 baud. : : Hmm, how do I find out how good it is? By looking at the docs to see if it supports PPS or not. PPS is Pulse Per Second and is a dedicated signal that pulses (typ 10mS) once per second. For serial devices, this is typically done by one of the extra RS-232 signals, DSR comes to mind. I suppose you could hook a scope up to the unit and see if any of the signals are acting like PPS. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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