Re: [ts-7000] syncing time on many TS-7550

[Walter Marvin <>]

NTP can actually sync to well under a millisecond. That does not include OP sys delays which are of the order of tenths of seconds. The only way to synch better than 1/5 of a second on TS Linux is to go sub opsys which means device drivers and hardware.

thanks

Walter

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From: Alex McLain <>
To:
Sent: Wednesday, October 24, 2012 12:34 PM
Subject: Re: [ts-7000] syncing time on many TS-7550

 

Have you looked into using the Precision Time Protocol?

http://en.wikipedia.org/wiki/Precision_Time_Protocol

http://ptpd.sourceforge.net/

"IEEE 1588 is designed to fill a niche not well served by either of the two dominant protocols, NTP and GPS. IEEE 1588 is designed for local systems requiring accuracies beyond those attainable using NTP. It is also designed for applications that cannot bear the cost of a GPS receiver at each node, or for which GPS signals are inaccessible."

[From Wikipedia]

-Alex

On Wed, Oct 24, 2012 at 6:30 AM, Angel <m("tierrasaltas.net","angel");" target="_blank" href="">> wrote:

 

Hi All,

I have an application where I need to sync many TS-7550 in the field to
within one tenth of a second of each other. I know I could do this with
a GPS and a PPS on each one but the cost and trouble to place the
antenna makes that a non-solution.

We have a hardware one pulse per second on the daughter card that is
deployed with system so we can generate one second data packages and
send them over TCP/IP. All the 7550 have a RTC and all have ntpd
running so I can discipline the hardware clocks to better than the
1/10th second requirement.

What I am at a loss on how to do is to sync the one second data packets
to the change of second of the RTC or any other stable time source.

TS says that the FPGA can be asked to make a one pulse per second but
that syncing the PPS pulse to the RTC is not sure.

If anyone has an idea on how to do this I would love to hear from you.

Regards,

Angel

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