Hello, We use NTP to time synchronize our Windows-based data collection/gateway systems. We have been running our software along with ntpd.exe successfully for several years. However, we are now facing a problem which I need help to resolve. Please note that I don't think there is anything wrong with ntpd.exe. I think I must ask our sub-vendor(s) the correct critical questions, and hope someone can help with formulating those questions.
Platform: Embedded hardware platform. Pentium III 700MHz CPU. Windows XP Embedded (Service Pack 2 level). NTP version: 4.2.0, downloaded from http://norloff.org/ntp/ The system clock is stable if we run NTP and our software in configurations like we have used previously. However, we have started utilizing a 3rd party software component (an OPC server) in some configurations, and it is in these configurations we experience problems with unstable system clocks. I have tried to isolate the problem the following way: 1. I start NTP. The system clock is stable and ntpq output indicates "everything's fine". NTP generates no entries in the event log after startup. 2. I start the 3rd party OPC server. I run ntpq -p and see a steadily increasing offset. It seems the OPC server influences the system clock negatively, and NTP finally has to reset the clock (event log entries): time reset +6.023474 s frequency error 6476 PPM exceeds tolerance 500 PPM NTP continues to reset the clock as long as the OPC server is running. This happens with about 15 minute intervals. 3. I stop the 3rd party OPC server. After some time the system clock is again stable and ntpq output indicates "everything's fine". NTP generates no entries in the event log. 4. I start the 3rd party OPC server again. The result is as described in step 2 above. I can't find anything in the OPC server documentation that indicates that it performs adjustments to the system clock. Which questions should I ask the OPC server and/or embedded hardware vendor? I am course also happy if someone has advise on further things to be checked. Thanks in advance. Geir _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
