Re: [ntp:questions] Can NTP sync within 12us for NBFM
On 29/04/14 03:59, Brian Inglis wrote: I understand that the NBFM transmitter starts with phase modulation then integrates, multiplies, and filters the result to the FM carrier frequency You are confusing carrier phase and audio phase. (FM modulation is mathematically the same as frequency modulation except for the frequency response of the audio. Both direct frequency modulation and phase modulation can be used. I believe NBFM is pre-emphasised such that, for most of the passband, it is actually more accurately described as phase modulation.) ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Issues installing ntpd on Win 7
On 29/04/2014 06:35, A C wrote: [] The original error messages were: A timeout was reached (3 milliseconds) while waiting for the Network Time Protocol Daemon service to connect. followed by The Network Time Protocol Daemon service failed to start due to the following error: The service did not respond to the start or control request in a timely fashion. No other errors or warnings. It's running now, the logs show synchronization and the only error is regarding the ability to generate the .rnd file. Thanks for that - although I'm no nearer to explaining the cause of the original problem. In my configuration, the .RND file is created in: C:\Tools\NTP\etc so most likely the problem was due to accepting the defaults (i.e. Program Files) in your first install. I recommend: C:\Tools\NTP rather than: C:\Program Files\NTP where C:\Tools is a completely open directory. The user typically needs to edit the ntp.conf file for their own servers and logging needs. -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
David Taylor david-tay...@blueyonder.co.uk.invalid wrote: On 26/04/2014 05:05, Harlan Stenn wrote: William Unruh writes: [] More recent ntpd combine server and client in one program. Not sure when that was. It's been the case for at least 20 years' time. This is something that may be different in the upcoming rewrite. H I hope not, as it would make much of the documentation out of date, and destroy much of the simplicity of deployment from the user's point of view. I would find it annoying to have to tell someone Oh, but if you want to pass on the time you need to uninstall what you have now and replace it with the client/server version. I think a useful separation would be between one part that is a server and a client of network time, and another part (many other parts) that are the interfaces to local refclocks. That could be in the form of a main program with loadable modules (like the Linux kernel), or by reducing the current ntpd to have zero refclocks, and have a set of separate programs that each serve up a refclock as an NTP source that the ntpd program just polls via 127.127.x.y which should be a localhost. Of course something would have to be arranged so that the stratum is not unnecessarily increased by one. This solution provides a lean ntpd program that is fit for most users, and it facilitates the easy addition of refclock drivers. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
David Taylor david-tay...@blueyonder.co.uk.invalid wrote: For Rob, I would suggest that each TX have a GPS/PPS reference with sky view, and that each PC was identical (e.g. all Raspberry Pi cards), and then getting them synced to with 12 microseconds should be easy. I Of course that is what we have. E.g. on a prototype here at home: ntpq -p remote refid st t when poll reach delay offset jitter == oPPS(0) .PPS.0 l2 16 3770.0000.000 0.000 xSHM(0) .GPS.0 l1 16 3770.0007.682 0.152 *SHM(1) .PPS.0 l 16 16 3770.0000.008 0.001 PPS(0) is a PPS input from a professional GPSDO connected to a COM port, SHM(1) is another GPS receiver interfaced via gpsd. Just to see how close they get and remain. Not Raspberry Pi (yet) but normal PC systems, but I know it is possible to get the system time within the desired 12 microseconds. Unfortunately that is not the same as performing some task like outputting audio at an accuracy of 12us, but that is the next challenge :-) ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Issues installing ntpd on Win 7
A C wrote: On 2014-04-28 22:23, David Taylor wrote: On 29/04/2014 05:51, A C wrote: [] Followed the same instructions, no dice. .. and what are the messages in the Windows Event Log(s)? The original error messages were: A timeout was reached (3 milliseconds) while waiting for the Network Time Protocol Daemon service to connect. followed by The Network Time Protocol Daemon service failed to start due to the following error: The service did not respond to the start or control request in a timely fashion. No other errors or warnings. Typical reasons for this behavior is if - a DLL is not found - the password for the user ntp doesn't match In such case you can try to run ntpd -n in a command line window. This runs ntpd as a usual program instead of a service. If a DLL is missing then you will get an appropriate popup error message telling which one. If ntpd starts in this mode (i.e. the command prompt doesn't reappear until you press Ctrl+C) but not as service then probably the ntp user's password doesn't match. The 4.2.6p5 package has been built with Visual Studio 2008, and even though current Windows versions (AFAIK) usually install the VS2008 runtime by default, we have recently had a few reports where this wasn't the case, and the VS2008 runtime had to be installed explicitely from http://www.microsoft.com/en-us/download/details.aspx?id=29 Please note you need the 32 bit version (x86) of the VS2008 runtime even on a 64 bit system since the Windows port of NTP actually can't be built as native 64 bit application. It's running now, the logs show synchronization and the only error is regarding the ability to generate the .rnd file. The .rnd file should be located in the etc\ subdirectory below the installation directory, and usually the installer and ntpd should have write access there. Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
Harlan Stenn wrote: This is something that may be different in the upcoming rewrite. Do you have a pointer to those plans? Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
Paul wrote: We have thousands of clients served from three S2 servers (so 0% need for refclock support). There are three S1 servers on campus (not yet in production). All three required building NTPd, one required a driver patch and one required building a kernel. It would be interesting to know why it should be required to rebuild the kernel. At least for Linux I can only imagine that this was at a time where neither nanosecond nor PPS support was provided by the standard Linux kernel, and usually you had to apply Ulrich Windl's patches against the vanilla kernel to get these features. Of course you had to rebuild the kernel in this case. Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
Harlan Stenn wrote: William Unruh writes: Well, ntpd could include timepps.h into ntpd source and point to it, instead of using the system one. Is there only one version of that file that is compatible with the places NTP will be built? What sort of bit-rot issues are there if we include a copy of the file in the NTP distribution? Maybe it would be sufficient to let the configure script print a summary of features which would be included, and which not. For example, if you forget to install the openSSL *headers* on a system where openSSL is normally available then the NTP package will silently be built without openSSL support, and when you use the resulting binaries you wonder why things don't work as expected. In a configure script for some other application I tried to build by myself there was a summary line printed indicating which features would be included, and which not, so I could see immediately that an optional feature I was expecting was obviously missing, and could install the required headers to have this optional feature supported. In case of NTP under Linux at least the Linux capabilities, openSSL, and PPS support come into my mind where a warning should be printed if these features are not included simply because some header files have not been installed on the build system. Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 12us for NBFM
On 2014-04-29 00:47, David Woolley wrote: On 29/04/14 03:59, Brian Inglis wrote: I understand that the NBFM transmitter starts with phase modulation then integrates, multiplies, and filters the result to the FM carrier frequency You are confusing carrier phase and audio phase. I omitted the preemphasis because that is applied to the audio before phase modulation of the IF, and I don't believe the 12PPMphase error would make any difference to the audio, but may affect the IF or carrier. (FM modulation is mathematically the same as frequency modulation except for the frequency response of the audio. Both direct frequency modulation and phase modulation can be used. I believe NBFM is pre-emphasised such that, for most of the passband, it is actually more accurately described as phase modulation.) ITYM FM ... PM, and the preemphasis flattens the audio spectrum to increase the resolution of the low level high frequency voice components and make better use of the available bandwidth. -- Take care. Thanks, Brian Inglis ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 12us for NBFM
On 2014-04-29 00:47, David Woolley wrote: On 29/04/14 03:59, Brian Inglis wrote: I understand that the NBFM transmitter starts with phase modulation then integrates, multiplies, and filters the result to the FM carrier frequency You are confusing carrier phase and audio phase. I omitted the preemphasis because that is applied to the audio before phase modulation of the IF, and I don't believe the 12PPMphase error would make any difference to the audio, but may affect the IF or carrier. (FM modulation is mathematically the same as frequency modulation except for the frequency response of the audio. Both direct frequency modulation and phase modulation can be used. I believe NBFM is pre-emphasised such that, for most of the passband, it is actually more accurately described as phase modulation.) ITYM FM ... PM, and the preemphasis flattens the audio spectrum to increase the resolution of the low level high frequency voice components and make better use of the available bandwidth. -- Take care. Thanks, Brian Inglis ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On Tue, Apr 29, 2014 at 12:12 AM, David Taylor david-tay...@blueyonder.co.uk.invalid wrote: I would find it annoying to have to tell someone Oh, but if you want to pass on the time you need to uninstall what you have now and replace it with the client/server version. Clearly there was confusion. I said I recall a distro that had two packages. E.g. - ntp-common with ntpd built as disable-all-clocks and - ntpd-server with ntpd built as enable-all-clocks. viz. nfs-common. There was a time when such things were considered good practice. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On Tue, Apr 29, 2014 at 4:35 AM, Rob nom...@example.com wrote: This solution provides a lean ntpd program that is fit for most users, and it facilitates the easy addition of refclock drivers. Sure or you just recognize that only one system in a million needs refclock support and assume anyone running a refclock needs to be smart enough to build ntpd with the requisite driver. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Issues installing ntpd on Win 7
Ok, so on a whim I purged it completely from the system. Installed from scratch and the same problem occurred, no starting up of the process. I let the installation complete without letting it try to start the service again. Then I simply performed a reinstall where it detected the existing installation and overwrote the files. It performed an update and suddenly the service starts up on its own. I have no idea why it did that but it took two back to back installations to fix it. When you said Did an update did you mean windows update? I did a quick google search from your first post with that error and it mentioned something about .NET needing to be installed? Maybe the windows update installed the necessary files since you said it was a fresh windows install. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
On 29/04/2014 09:41, Rob wrote: [] Of course that is what we have. E.g. on a prototype here at home: ntpq -p remote refid st t when poll reach delay offset jitter == oPPS(0) .PPS.0 l2 16 3770.0000.000 0.000 xSHM(0) .GPS.0 l1 16 3770.0007.682 0.152 *SHM(1) .PPS.0 l 16 16 3770.0000.008 0.001 PPS(0) is a PPS input from a professional GPSDO connected to a COM port, SHM(1) is another GPS receiver interfaced via gpsd. Just to see how close they get and remain. Not Raspberry Pi (yet) but normal PC systems, but I know it is possible to get the system time within the desired 12 microseconds. Unfortunately that is not the same as performing some task like outputting audio at an accuracy of 12us, but that is the next challenge :-) Indeed, and you will likely want to look at very matched systems (PCs and transmitters - the whole chain), and having the minimum latency in the OS. I'm not familiar enough with Linux to know which variant to recommend, or whether FreeBSD or some other OS might be better. When comparing, be aware that there can be significant delays in things like RS-232 level converters etc., especially if they have rise-time limiting. Not to mention any delays in the COM port control lines! It sounds an interesting project. -- 73, David GM8ARV Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Issues installing ntpd on Win 7
On 29/04/2014 14:40, Jason Rabel wrote: Ok, so on a whim I purged it completely from the system. Installed from scratch and the same problem occurred, no starting up of the process. I let the installation complete without letting it try to start the service again. Then I simply performed a reinstall where it detected the existing installation and overwrote the files. It performed an update and suddenly the service starts up on its own. I have no idea why it did that but it took two back to back installations to fix it. When you said Did an update did you mean windows update? I did a quick google search from your first post with that error and it mentioned something about .NET needing to be installed? Maybe the windows update installed the necessary files since you said it was a fresh windows install. Windows .NET is not required for the Meinberg NTP port. I think Jason meant using the Update files option of the Meinberg installer. -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Issues installing ntpd on Win 7
Jason Rabel wrote: Ok, so on a whim I purged it completely from the system. Installed from scratch and the same problem occurred, no starting up of the process. I let the installation complete without letting it try to start the service again. Then I simply performed a reinstall where it detected the existing installation and overwrote the files. It performed an update and suddenly the service starts up on its own. I have no idea why it did that but it took two back to back installations to fix it. When you said Did an update did you mean windows update? I did a quick google search from your first post with that error and it mentioned something about .NET needing to be installed? Maybe the windows update installed the necessary files since you said it was a fresh windows install. I bet the VS2008 runtime has been installed together with some update, and that fixed the problem. See also my other post. Martin -- Martin Burnicki Meinberg Funkuhren Bad Pyrmont Germany ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP.log interpretation
As a follow up to this discussion which has been very helpful to me wanted to say we are moving towards adding 4 internal time servers (NTP Unix based.. non-x86 hdw) to the two Windows domain controllers that are running NTP as well. All 6 will be synced externally and will serve all our internal NTP client systems. The 'load balancer' will be removed and all ntp.conf files will have all 6 time server entries. Thanks to everyone for the helpful and informative input. -Greg ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On 29/04/2014 14:40, Paul wrote: [] Sure or you just recognize that only one system in a million needs refclock support and assume anyone running a refclock needs to be smart enough to build ntpd with the requisite driver. However, many of my users who use PPS or other ref-clocks run Windows, and they do not have either the required tools or skills to recompile. The compiler alone is a 1 GB download. These days a slightly larger executable including the ref-clocks is a very small inconvenience compared to having to rebuild. Another issue is the time taken to rebuild - you are looking at nearly an hour on the Raspberry Pi, for example. -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On Tue, Apr 29, 2014 at 10:12 AM, David Taylor david-tay...@blueyonder.co.uk.invalid wrote: However, many of my users who use PPS or other ref-clocks run Windows The subject line is Attn LINUX distributors. And it's really about timepps.h ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
David Taylor david-tay...@blueyonder.co.uk.invalid wrote: On 29/04/2014 14:40, Paul wrote: [] Sure or you just recognize that only one system in a million needs refclock support and assume anyone running a refclock needs to be smart enough to build ntpd with the requisite driver. However, many of my users who use PPS or other ref-clocks run Windows, and they do not have either the required tools or skills to recompile. The compiler alone is a 1 GB download. These days a slightly larger executable including the ref-clocks is a very small inconvenience compared to having to rebuild. Another issue is the time taken to rebuild - you are looking at nearly an hour on the Raspberry Pi, for example. But with a modular approach you would not need to rebuild to add a standard refclock, that would just be the installation of another package containing the precompiled refclock or refclock bundle. That is no different from having a program like Perl as a base, and a lot of packages containing Perl modules for specific tasks. The advantage would be that one can actually ADD an own refclock without having to go through long and painful discussions with package maintainers. Or in the case discussed in this thread, one could compile a single refclock that was omitted due to distributor oversight, and keep the remainder of ntpd standard and candidate for automatic updates. Even when the whole thing (ntpd and refclocks) would be distributed in a single package, it would be possible to add new refclocks to that. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
David Taylor david-tay...@blueyonder.co.uk.invalid wrote: Unfortunately that is not the same as performing some task like outputting audio at an accuracy of 12us, but that is the next challenge :-) Indeed, and you will likely want to look at very matched systems (PCs and transmitters - the whole chain), and having the minimum latency in the OS. I'm not familiar enough with Linux to know which variant to recommend, or whether FreeBSD or some other OS might be better. I already learned how this can be achieved in Alsa and it looks good. When comparing, be aware that there can be significant delays in things like RS-232 level converters etc., especially if they have rise-time limiting. Not to mention any delays in the COM port control lines! I first was afraid of that, and I wondered if the 10-30us pulse typically output by a GPSDO could be interfaced using an RS232 line. I considered it better to use a parallel port for this. However, parallel ports are not present on modern systems, USB replacements are no good for this purpose, and adding a parallel port requires a slot, also something usually on short supply. However, I now realize that 10us is equivalent to 100.000 bps, and all serial ports operate to 115.200 bps some even to 921.600 bps. So this probably will not be an issue after all. It sounds an interesting project. Yes, we sometimes need to try something new (at least to us) or else ham radio becomes boring pretty quickly. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On 29/04/2014 15:35, Rob wrote: [] But with a modular approach you would not need to rebuild to add a standard refclock, that would just be the installation of another package containing the precompiled refclock or refclock bundle. That is no different from having a program like Perl as a base, and a lot of packages containing Perl modules for specific tasks. The advantage would be that one can actually ADD an own refclock without having to go through long and painful discussions with package maintainers. Or in the case discussed in this thread, one could compile a single refclock that was omitted due to distributor oversight, and keep the remainder of ntpd standard and candidate for automatic updates. Even when the whole thing (ntpd and refclocks) would be distributed in a single package, it would be possible to add new refclocks to that. I agree it sound nice in theory, but you need to find a mechanism which is supported in all the operating systems which NTP supports, and document how the users can add ref clocks. To me, it's all completely unnecessary - the number of folk /adding/ ref-clocks must be far smaller than those /using/ ref-clocks! -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On 29/04/2014 15:33, Paul wrote: On Tue, Apr 29, 2014 at 10:12 AM, David Taylor david-tay...@blueyonder.co.uk.invalid wrote: However, many of my users who use PPS or other ref-clocks run Windows The subject line is Attn LINUX distributors. And it's really about timepps.h .. and I would be happy if the Raspberry Pi Linux variant did not have tickless set, as it means you need to recompile the kernel to get the best NTP performance. But the threat of breaking NTP into two separate parts had been mentioned, and it was that which I was addressing. If the server variant was the only one available for Windows it would not be a problem. Having multiple variants does increase the support costs. -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 12us for NBFM
On 2014-04-29, Brian Inglis brian.ing...@shaw.ca wrote: On 2014-04-29 00:47, David Woolley wrote: On 29/04/14 03:59, Brian Inglis wrote: I understand that the NBFM transmitter starts with phase modulation then integrates, multiplies, and filters the result to the FM carrier frequency You are confusing carrier phase and audio phase. I omitted the preemphasis because that is applied to the audio before phase modulation of the IF, and I don't believe the 12PPMphase error would make any difference to the audio, but may affect the IF or carrier. I cannot see how. The FM does not really care what the signal is. If the signal is late by 7 hours, never mind 12us, it does not care. And also we are talking about the time difference in the audio signal between two different transmitters. Now if both signals are of equal strength at the receiver, then the phase difference between the two audio signals might be important, But again, not 12us. Maybe 200us might start to show some effects. (FM modulation is mathematically the same as frequency modulation except for the frequency response of the audio. Both direct frequency modulation and phase modulation can be used. I believe NBFM is pre-emphasised such that, for most of the passband, it is actually more accurately described as phase modulation.) ITYM FM ... PM, and the preemphasis flattens the audio spectrum to increase the resolution of the low level high frequency voice components and make better use of the available bandwidth. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Issues installing ntpd on Win 7
On 2014-04-29 00:33, David Taylor wrote: On 29/04/2014 06:35, A C wrote: [] The original error messages were: A timeout was reached (3 milliseconds) while waiting for the Network Time Protocol Daemon service to connect. followed by The Network Time Protocol Daemon service failed to start due to the following error: The service did not respond to the start or control request in a timely fashion. No other errors or warnings. It's running now, the logs show synchronization and the only error is regarding the ability to generate the .rnd file. Thanks for that - although I'm no nearer to explaining the cause of the original problem. In my configuration, the .RND file is created in: C:\Tools\NTP\etc so most likely the problem was due to accepting the defaults (i.e. Program Files) in your first install. I recommend: C:\Tools\NTP rather than: C:\Program Files\NTP where C:\Tools is a completely open directory. The user typically needs to edit the ntp.conf file for their own servers and logging needs. I installed to C:\NTP so there's something else wrong. The ntpd account that was created has full access to that directory. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Issues installing ntpd on Win 7
On 2014-04-29 03:14, Martin Burnicki wrote: A C wrote: On 2014-04-28 22:23, David Taylor wrote: On 29/04/2014 05:51, A C wrote: [] Followed the same instructions, no dice. .. and what are the messages in the Windows Event Log(s)? The original error messages were: A timeout was reached (3 milliseconds) while waiting for the Network Time Protocol Daemon service to connect. followed by The Network Time Protocol Daemon service failed to start due to the following error: The service did not respond to the start or control request in a timely fashion. No other errors or warnings. Typical reasons for this behavior is if - a DLL is not found - the password for the user ntp doesn't match In such case you can try to run ntpd -n in a command line window. This runs ntpd as a usual program instead of a service. If a DLL is missing then you will get an appropriate popup error message telling which one. This might be it. I chose not to install the OpenSSL library (unchecked the option in the installer) because I don't use any authentication or other crypto for ntpd. When I reinstalled the second time, it simply wrote the DLL into place (it said as much with a dialog box stating something to the effect of OpenSSL installed but I'm fairly certain libeay32.dll was not present when I first looked in the install directory and showed up after the reinstall) and then it worked. So even though SSL is optional in the installer it appears that it is very much not optional for the daemon itself. I may try to uninstall, purge and try again to see if that really was it. If ntpd starts in this mode (i.e. the command prompt doesn't reappear until you press Ctrl+C) but not as service then probably the ntp user's password doesn't match. The 4.2.6p5 package has been built with Visual Studio 2008, and even though current Windows versions (AFAIK) usually install the VS2008 runtime by default, we have recently had a few reports where this wasn't the case, and the VS2008 runtime had to be installed explicitely from http://www.microsoft.com/en-us/download/details.aspx?id=29 Please note you need the 32 bit version (x86) of the VS2008 runtime even on a 64 bit system since the Windows port of NTP actually can't be built as native 64 bit application. It's running now, the logs show synchronization and the only error is regarding the ability to generate the .rnd file. The .rnd file should be located in the etc\ subdirectory below the installation directory, and usually the installer and ntpd should have write access there. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
On 2014-04-29, Rob nom...@example.com wrote: David Taylor david-tay...@blueyonder.co.uk.invalid wrote: Unfortunately that is not the same as performing some task like outputting audio at an accuracy of 12us, but that is the next challenge :-) Indeed, and you will likely want to look at very matched systems (PCs and transmitters - the whole chain), and having the minimum latency in the OS. I'm not familiar enough with Linux to know which variant to recommend, or whether FreeBSD or some other OS might be better. I already learned how this can be achieved in Alsa and it looks good. When comparing, be aware that there can be significant delays in things like RS-232 level converters etc., especially if they have rise-time limiting. Not to mention any delays in the COM port control lines! I first was afraid of that, and I wondered if the 10-30us pulse typically output by a GPSDO could be interfaced using an RS232 line. I considered it better to use a parallel port for this. However, parallel ports are not present on modern systems, USB replacements are no good for this purpose, and adding a parallel port requires a slot, also something usually on short supply. However, I now realize that 10us is equivalent to 100.000 bps, and all serial ports operate to 115.200 bps some even to 921.600 bps. And many serial ports will handle TTL level just fine, without any serial level converters. (On RPi, there is a limit of something line 3V on the input pins, so putting out the 5-20V of a serial level converter could be very unhealthy.) So this probably will not be an issue after all. The problem is not the electronics, it is the response of the system to the interrupt. That interrupt processing time is in the usec range. It sounds an interesting project. Yes, we sometimes need to try something new (at least to us) or else ham radio becomes boring pretty quickly. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
William Unruh un...@invalid.ca wrote: The problem is not the electronics, it is the response of the system to the interrupt. That interrupt processing time is in the usec range. This does not really matter when it is constant. And my experience is that the jitter on the PPS refclock is usually 0, 1 or 2us when I check it. On a newer server that has just been configured for this task it is the same: remote refid st t when poll reach delay offset jitter == oPPS(0) .PPS.0 l 16 16 3770.000 -0.001 0.001 (the GPSDO is still synchronizing, things may be even better after that) ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Issues installing ntpd on Win 7
On 2014-04-29 07:00, Martin Burnicki wrote: Jason Rabel wrote: Ok, so on a whim I purged it completely from the system. Installed from scratch and the same problem occurred, no starting up of the process. I let the installation complete without letting it try to start the service again. Then I simply performed a reinstall where it detected the existing installation and overwrote the files. It performed an update and suddenly the service starts up on its own. I have no idea why it did that but it took two back to back installations to fix it. When you said Did an update did you mean windows update? I did a quick google search from your first post with that error and it mentioned something about .NET needing to be installed? Maybe the windows update installed the necessary files since you said it was a fresh windows install. I bet the VS2008 runtime has been installed together with some update, and that fixed the problem. See also my other post. All of the runtimes were installed long before I tried to install ntpd including any outstanding Microsoft patches, updates, etc. I had installed several other programs that needed the various runtimes first. The installation of ntpd was one of the last things I did. I think it just came down to libeay32.dll not being installed the first time and the reinstall/update simply put that back in on its own without prompting. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Issues installing ntpd on Win 7
On 2014-04-29 06:40, Jason Rabel wrote: Ok, so on a whim I purged it completely from the system. Installed from scratch and the same problem occurred, no starting up of the process. I let the installation complete without letting it try to start the service again. Then I simply performed a reinstall where it detected the existing installation and overwrote the files. It performed an update and suddenly the service starts up on its own. I have no idea why it did that but it took two back to back installations to fix it. When you said Did an update did you mean windows update? I did a quick google search from your first post with that error and it mentioned something about .NET needing to be installed? Maybe the windows update installed the necessary files since you said it was a fresh windows install. No, the ntpd installer performed its own update which simply amounted to rewriting all the files it had just installed but apparently added libeay32.dll to the mix which wasn't present before. windows Update had already been done long before I tried to install ntpd. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
On Tue, Apr 29, 2014 at 11:21 AM, David Taylor david-tay...@blueyonder.co.uk.invalid wrote: But the threat of breaking NTP into two separate parts had been mentioned, and it was that which I was addressing Sure. But I really have no idea what Harlan was speaking to there and, for Windows users, I think the issue is still largely a distro concern. In this case, if at some unknown future time ntp is further partitioned, what Meinberg does is more important than what's in the tar ball. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can NTP sync within 1ms
William Unruh un...@invalid.ca wrote: On 2014-04-29, Rob nom...@example.com wrote: William Unruh un...@invalid.ca wrote: The problem is not the electronics, it is the response of the system to the interrupt. That interrupt processing time is in the usec range. This does not really matter when it is constant. And my experience is that the jitter on the PPS refclock is usually 0, 1 or 2us when I check it. That sounds like 100% variability. And the serial port level converter time delay is much more constant. Also look at the jitter when the system is heavily loaded with disk input/output or network load. This is included in the above figure. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Attn Linux distributors - pse include PPS
Martin Burnicki writes: Harlan Stenn wrote: This is something that may be different in the upcoming rewrite. Do you have a pointer to those plans? Not yet - we can start a discussion topic on the wiki and I doubt I'll have time to do much with it for at least a month. Right now I have a few significantly hotter fires to put out (for example, you may have noticed there haven't been any tarball snapshots in a while - hardware problems). H ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
