Cesium-based grandmasters can cost a lot of money but I think that GPSDO-based ones are a lot cheaper.
On Thu, Aug 1, 2013 at 11:48 PM, Daniel Mendes <dmend...@gmail.com> wrote: > > This is true, but what´s needed to generate the sync packets? I think they > call them "Grand Masters", and cost a lot of money... Is there any cheap > approach for this end of the problem? > > Daniel > > Em 31/07/2013 08:03, Bob Camp escreveu: >> >> Hi >> >> A number of the chip guys will sell you micro's that have one or more 1588 >> ethernet ports on them. Some of them are in the sub $10 range. With a bit of >> Time Nut attention, they seem to be capable of well under 1 us performance. >> If you have a daisy chain network they will do what you need without any >> switches. >> >> As mentioned above, if your network has modern (gigabit rather than 10 >> megabit) switches on it, you can likely get to 1 us without any fancy time >> stamping switches. There are a few other minor details you would want to pay >> attention to, but they are manageable for a shop floor network. >> >> Bob >> >> On Jul 31, 2013, at 12:19 AM, Bill Hawkins <b...@iaxs.net> wrote: >> >>> Group, >>> >>> Has anyone used IEEE 1588 to synchronize clocks on an Ethernet network? >>> >>> I was involved in the design of time sync for Foundation Fieldbus circa >>> 2000. >>> We needed one millisecond accuracy, so we went with SNTP on local >>> networks. >>> I've just seen an ad for a switch that can do 1588, and looked up what >>> it does. >>> >>> Microsecond accuracy is impressive, but what does it cost? >>> >>> Industrial sensors are generally sampled at about 10 millisecond >>> intervals out >>> to several seconds. SNTP would appear to be very adequate for time >>> stamps as >>> there is uncertainty introduced by when the computer gets around to >>> sampling >>> the sensor in its sampling and control cycle. >>> >>> Any thoughts appreciated. >>> >>> Bill Hawkins >>> >>> _______________________________________________ >>> 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. _______________________________________________ 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.
