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Unfortunately, this is not a valid test, which is typical of Technologic. First of all it is anedotal, and no real measurement is made. Second it is probably not run long enough to make a statically significant conclusion (although they don't say how long their "burn in" runs) Third it is probably run with a simplistic program which are all the same, and presents no load or variation on the system.
you have been warned Walter From: Angel <> To: Sent: Wednesday, October 24, 2012 5:37 PM Subject: Re: [ts-7000] syncing time on many TS-7550 Hi All,
Just as an update. I got this from Grant at TS. When TS-7550s are tested with the TS-752, we actually run a stress test that proves out the validity of a software solution. 20 or more units are placed on a burn-in rack and they automatically run a burn-in/test script. They synchronize their system time from our local NTP server, and then they begin toggling relays and LEDs at 1Hz. The goal of this is just to test the relays, but the ear and eye can tell that they are reasonably synchronized and all the relays click as one. The timing was implemented with the attached C program and a shell wrapper that uses it to wait for the right time to toggle things using ts7500ctl. We are coding some stuff now and will have some results in a few days, we need to butcher some harware. ntpd displines the TS clock to just a few milliseconds and I suspect that it what I am going to do will work. If anyone is interested in the code snippet that Grant sent just ask. regards, Angel On 10/24/2012 04:30 PM, Ken Lu wrote: > > I did on TS-7400(connect to laptop by Ethernet), modified a telnet > program, to synchronize PC's time, which comes from GPS connected to > PC. But found that TS-Linux's date command can only set to the > minute, so need to wait within a minute, depends on start setting time. > > --- On *Wed, 10/24/12, Walter Marvin /<>/* wrote: > > > From: Walter Marvin <> > Subject: Re: [ts-7000] syncing time on many TS-7550 > To: "" <> > Received: Wednesday, October 24, 2012, 10:36 AM > > You could make a real time clock driver and use the hardware's > alarm feature. this may mean using a different clock chip . > Fortunately there are a number of IIC clock chips that can do this. > > > ---------------------------------------------------------- > *From:* Angel <> > *To:* > *Sent:* Wednesday, October 24, 2012 9:30 AM > *Subject:* [ts-7000] syncing time on many TS-7550 > > 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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