I was involved in some work on industrial controls that used 1588 for timing. We only needed microsecond accuracy, and it did that easily - the basic hardware is simple, we were using STM32 microcontrollers with the DP83640 PHY. Since the MCU required a PHY anyway, the additional cost for the IEEE1588 support was about $3.50/unit ($5 rather than $1.50 in 1000 up quantities).
The PHY chip also has a (programmable) clock output locked to the 1588 timing, but it appeared to have quite a lot of phase noise on it - I didn't bother doing any detailed measurements because we weren't actually using it. On Wed, Jul 31, 2013 at 12:19 PM, Bill Hawkins <[email protected]> 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 -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ 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.
