Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
From: Adam Kumiszcza It will be connected via a short cable (1,5 m or less) to one computer. The second will join much later, I will worry about splitting the signal then. Other computers would be in different rooms, so I would need another time source. My question was rather if stacking another board with serial port on it would be a good idea. I'm thinking of using PPS signal there directly via GPIO. And maybe NMEA, too. Cheers, Adam = Adam, You may be unable to stack another board on top, but that depends on the boards, of course. I would suggest using the network connection between the computers (with the Internet as a backup) for getting the coarse seconds. You then need to know what voltage level is required on the second computer for its serial connections - +/- 12 V or TTL levels. If it's a standard serial port on the computer, use a RS232-TTL converter just to connect the PPS line to the DCD pin (1 on a DB9 connector). No need to the TX/RX lines, just ground and PPS. I had hoped that someone else on the group who had real-world experience of distributing PPS might chip in Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Wed, Sep 25, 2019 at 8:01 PM David J Taylor via time-nuts < time-nuts@lists.febo.com> wrote: > From: Adam Kumiszcza > > Hi again! > > My raspi is now in a new location. The GPS signal is fine, the window is > not south-facing, but the antenna is outside the window attached to a metal > windowsill, and there are no buildings nearby. > I'm coming back to the idea of distributing PPS signal. Do you think such a > contraption could work? > > https://botland.com.pl/pl/raspberry-pi-hat-komunikacja/11707-serial-pi-plus-max3232-interfejs-rs232-dla-raspberry-pi-7426787870194.html > > I mean, stacking it over the uputronics board and soldiering some pins. > The MAX3232 chip is the same as on these kind of devices: > > https://www.ebay.com/itm/MAX3232-RS232-to-TTL-Serial-Port-Converter-Module-DB9-Connector-MAX232/262241627343 > > Cheers, > Adam > === > > Adam, > > You need to consider what cable you will use, how many devices you need to > feed, and what distance is involved. I've fed a couple of PCs from the > same > RS232 device, just the data out and CD (PPS) lines, of course. Not > paralleling the data into the GPS device. One PC is ~4m away, and the two > signals are fed over a twin-pair coaxial cable. Likely a 3-core > unscreened > cable would also be OK over such a short distance. The other PC is about > a > metre away. > > If you're talking about ten PCs I would have a number of TTL to RS232 > converters, each feeding 2-3 PCs, or a controlled impedance cable (50 or > 75 > ohms) with tap-offs along the cable and a termination at the far end. The > old thin-wire Ethernet comes to mind. > > But others here have more experience than me, though, and may be able to > recommend surplus units to do the job. > > Cheers, > David > It will be connected via a short cable (1,5 m or less) to one computer. The second will join much later, I will worry about splitting the signal then. Other computers would be in different rooms, so I would need another time source. My question was rather if stacking another board with serial port on it would be a good idea. I'm thinking of using PPS signal there directly via GPIO. And maybe NMEA, too. Cheers, Adam ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
From: Adam Kumiszcza Hi again! My raspi is now in a new location. The GPS signal is fine, the window is not south-facing, but the antenna is outside the window attached to a metal windowsill, and there are no buildings nearby. I'm coming back to the idea of distributing PPS signal. Do you think such a contraption could work? https://botland.com.pl/pl/raspberry-pi-hat-komunikacja/11707-serial-pi-plus-max3232-interfejs-rs232-dla-raspberry-pi-7426787870194.html I mean, stacking it over the uputronics board and soldiering some pins. The MAX3232 chip is the same as on these kind of devices: https://www.ebay.com/itm/MAX3232-RS232-to-TTL-Serial-Port-Converter-Module-DB9-Connector-MAX232/262241627343 Cheers, Adam === Adam, You need to consider what cable you will use, how many devices you need to feed, and what distance is involved. I've fed a couple of PCs from the same RS232 device, just the data out and CD (PPS) lines, of course. Not paralleling the data into the GPS device. One PC is ~4m away, and the two signals are fed over a twin-pair coaxial cable. Likely a 3-core unscreened cable would also be OK over such a short distance. The other PC is about a metre away. If you're talking about ten PCs I would have a number of TTL to RS232 converters, each feeding 2-3 PCs, or a controlled impedance cable (50 or 75 ohms) with tap-offs along the cable and a termination at the far end. The old thin-wire Ethernet comes to mind. But others here have more experience than me, though, and may be able to recommend surplus units to do the job. Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Thu, Aug 8, 2019 at 7:00 PM David J Taylor via time-nuts < time-nuts@lists.febo.com> wrote: > Hi everybody! My first post here, I hope the subject is adequate for this > mailing list. > > I'm using a tiny layer 1 NTP server consisting of Raspberry Pi 3B+ with > Ublox MAX-M8Q expansion board providing GNSS (currently GPS, Galileo and > Glonass, sometimes I switch to Beidou, too) reference with PPS + a simple > patch antenna hanging near the window. Offset, jitter and rms are most > often smaller than 1 µs. The server is included in NTP pool. > > I'm using several Windows 10 machines on the same LAN, all using NTP client > software from Meinberg. The typical offset and jitter in those are about > 100-500 µs. I would like to make it lower. > [] > Thanks in advance for any suggestions! > > Adam Kumiszcza > > > Adam, > > You could feed the PPS signal to the Windows PCs as one way of making the > performance better: > > https://www.satsignal.eu/ntp/setup.html > > Performance: > > https://www.satsignal.eu/mrtg/performance_ntp.php#windows-stratum-1 > Cheers, > David > Hi again! My raspi is now in a new location. The GPS signal is fine, the window is not south-facing, but the antenna is outside the window attached to a metal windowsill, and there are no buildings nearby. I'm coming back to the idea of distributing PPS signal. Do you think such a contraption could work? https://botland.com.pl/pl/raspberry-pi-hat-komunikacja/11707-serial-pi-plus-max3232-interfejs-rs232-dla-raspberry-pi-7426787870194.html I mean, stacking it over the uputronics board and soldiering some pins. The MAX3232 chip is the same as on these kind of devices: https://www.ebay.com/itm/MAX3232-RS232-to-TTL-Serial-Port-Converter-Module-DB9-Connector-MAX232/262241627343 Cheers, Adam ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
Adam Kumiszcza writes: > After all your tips I just checked whether the roof itself blocks the > signal or not. I put the patch antenna together with a metal disk on top of > a high wardrobe, close to ceiling, and I guess it is the best position > here. See attached screenshots. Good, that looks more sensible. > Unfortunately, I will have to move this ntp server to another location (or > make another one and leave this one here). It will not have access to south > facing window there, only west is possible. Since the GPS antennas have a built-in LNA, you can extend the cable quite a bit if you use something that's not too lossy without impacting the performance much. The captive cable on these antennas is almost always the cheapest thing that will work (RG-174 mostly), so I tend to buy them with the shortest option on offer, then extend with H195 or LMR400 coax depending on required length and how much space is available for running the cable. You need to be careful when specifying the connectors, the GPS antennas are plain SMA (not RP-SMA) and many of the cables you'll find are for WLAN extension (which mainly uses RP-SMA). If you need a pair of extensions, look for twin-coax; you can easily separate the two individual cables and it's usually cheaper than getting two single cables of the same make and length. Your other option is running the rasPi headless from a PoE segment, then you can move it with the antenna relatively easily. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ Samples for the Waldorf Blofeld: http://Synth.Stromeko.net/Downloads.html#BlofeldSamplesExtra ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
From: Adam Kumiszcza [] I didn't have to stick to "good enough", David :) Unfortunately, I will have to move this ntp server to another location (or make another one and leave this one here). It will not have access to south facing window there, only west is possible. Best regards, Adam Adam, I take more of an engineering approach - stop when it's good enough! I have too many other things which interest me (like frequency measurement) to spend time past when "good enough" for NTP is achieved. But you might like to try the Raspberry Pi 4 with a slightly faster CPU, and significantly better I/O, for enhanced performance. Particularly as you are using a Raspberry Pi, that's likely to be the limiting factor, not the number of satellites you can see. For that reason, I would suggest that a west-facing window (or outside same) would be fine. Monitor it occasionally, of course. However, having three or four stratum-1 NTP servers is a good idea, particularly when they are such a low cost as the Raspberry Pi solution can achieve. The last few Raspberry Pi zero projects I've housed I've automatically added a Chinese GPS board, so they become stratum-1 NTP locked rather than relying on LAN or Wi-Fi sync. With just two, you're never sure which is right! Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Mon, Aug 12, 2019 at 10:14 PM Achim Gratz wrote: > Adam Kumiszcza writes: > > I've made a ca. 10.5 cm metal disc cut from an old car radio chasis and > put > > it under my gps antenna. It does not hang now, but lays on the window > sill, > > facing up. > > That way you changed three variables in one go. You'd be better off > changing one single thing each time so you can see what changes cause > which results. You do have a patch antenna (rectangular flat shape), not a quadrifilar helix, do you? > It's a normal patch antenna, bought together with gps addon card: https://store.uputronics.com/index.php?route=product/product=60_65_id=67 After all your tips I just checked whether the roof itself blocks the signal or not. I put the patch antenna together with a metal disk on top of a high wardrobe, close to ceiling, and I guess it is the best position here. See attached screenshots. On Mon, Aug 12, 2019 at 5:01 PM David J Taylor via time-nuts < time-nuts@lists.febo.com> wrote: > My gut feeling is that is you're seeing just a 1 dB change, it /may/ not be > worth bothering with. On the other hand, don't throw dB away unnecessarily! > [..] If you're seeing six, > say, satellites at a minimum - likely it's good enough. I didn't have to stick to "good enough", David :) Unfortunately, I will have to move this ntp server to another location (or make another one and leave this one here). It will not have access to south facing window there, only west is possible. Best regards, Adam ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
Adam Kumiszcza writes: > I've made a ca. 10.5 cm metal disc cut from an old car radio chasis and put > it under my gps antenna. It does not hang now, but lays on the window sill, > facing up. That way you changed three variables in one go. You'd be better off changing one single thing each time so you can see what changes cause which results. You do have a patch antenna (rectangular flat shape), not a quadrifilar helix, do you? > I cannot see any difference between these positions. I've made 10 > measurement for each position, getting 12 SNR values for satellites for > each measurement and then calculated the average of these. Looking at your gpsmon pictures you seem to see the low elevation sats at very similar SNR as (most) high elevation ones. Any RF reflecting things around in your neighbourhood? Also, as David already mentioned, thermo-pane windows are actually damping RF quite significantly and even reflect them at low incidence angles. You might try a few minutes with an open window and otherwise unchanged antenna location to see what happens. > Hanging antenna had 25.18 SNR average (2.21 standard deviation). Antenna on > a ground plane had 26.10 SNR average (2.08 standard deviation). The constellation providing your fix (four satellites minimum) should probably all be well over 30dB, peaking in the mid 40dB SNR range. > If I take into account single high elevation satellite with good SNR > (satellite 26 in the examples), the new placement and ground plane even > lowered it :( You may have to experiment with antenna position a bit more. I have seen more than 15dB changes from rather small changes in antenna placement. It's definitely worth experimenting a bit to find one that is good over the full cycle of the GPS constellation. > I guess the real benefit of the ground plane would be if the antenna was > outside, or my measurement method was wrong? No, the ground plane (if your antenna needs one, not all do) is there to improve the gain in the forward direction and make the elevation pattern more uniform. Outside oir inside doesn't matter, but antennas are influenced by many things in their near-field region (at around 1.5GHz, a few wavelengths at most, so ~30…50cm). Again, you may be too close to the window pane for instance. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ Factory and User Sound Singles for Waldorf rackAttack: http://Synth.Stromeko.net/Downloads.html#WaldorfSounds ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
From: Adam Kumiszcza [] If I take into account single high elevation satellite with good SNR (satellite 26 in the examples), the new placement and ground plane even lowered it :( I guess the real benefit of the ground plane would be if the antenna was outside, or my measurement method was wrong? Best regards, Adam === Adam, My gut feeling is that is you're seeing just a 1 dB change, it /may/ not be worth bothering with. On the other hand, don't throw dB away unnecessarily! If the GPS can't "see" through the house (look at the polar plot), likely tilting the puck down slightly (say 20 degrees) /might/ give a slight benefit (higher gain for lower angle satellites). If you're seeing six, say, satellites at a minimum - likely it's good enough. Not sure this list approves of "good enough" - LOL! Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Sun, Aug 11, 2019 at 8:01 PM Achim Gratz wrote: > Adam Kumiszcza writes: > >> The key here is to have some conducting magnetic material under the > >> antenna, not just sitting on its own. > > > > My GPS antenna hangs on the window handle and still gives the good > result. > > It's on the south facing window. Unfortunately, in the new location I > will > > have access only to west facing window. > > You should orient it correctly so that it is facing up, not simply > dangling it from the cable. GPS antennas are directional. > > > Why is it good to have some conducting magnetic material under the > antenna? > > Is it to reduce multipath? > > The GPS dielectric patch antennas are designed to perform best with a > ground plane. The optimum size varies a bit, but between 10…14cm in > diameter is about right. [...] > Thanks for all the info! I've made a ca. 10.5 cm metal disc cut from an old car radio chasis and put it under my gps antenna. It does not hang now, but lays on the window sill, facing up. I cannot see any difference between these positions. I've made 10 measurement for each position, getting 12 SNR values for satellites for each measurement and then calculated the average of these. Hanging antenna had 25.18 SNR average (2.21 standard deviation). Antenna on a ground plane had 26.10 SNR average (2.08 standard deviation). https://docs.google.com/spreadsheets/d/1lvGFTQS62MqiQALjHmWFZRY3hb5O1OqANFGBhnCaEUo/edit?usp=sharing 2 example screenshots from gpsmon included (before and after the change of position) If I take into account single high elevation satellite with good SNR (satellite 26 in the examples), the new placement and ground plane even lowered it :( I guess the real benefit of the ground plane would be if the antenna was outside, or my measurement method was wrong? Best regards, Adam ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
You already have a PPS signal from your existing GPS, so I was thinking simply of distributing that the the Windows PCs, and feeding it to the serial port's DCD signal. I will try that. I guess you can connect serial port directly to my Uputronics expansion card ( https://store.uputronics.com/index.php?route=product/product=60_64_id=81) while still attached to Raspberry Pi. Problem is, I'm a software, not a hardware guy. No idea about soldering. Time to learn a new skill :) If the PC doesn't have a serial port, check on the motherboard because there are sometimes serial port headers left unconnected by the PC manufacturer. That's exactly in my case. Motherboard manual says the serial port expansion is sold separately. [..] Check with your Android mobile phone what the GPS signal levels actually are in your possible locations - I think Apple don't allow you to access that information. I don't have access to any Android device :( I'll try to use gpsmon or other tool to check GPS signal level (S/N ratio of satellites should be sufficient, I guess?). The key here is to have some conducting magnetic material under the antenna, not just sitting on its own. My GPS antenna hangs on the window handle and still gives the good result. It's on the south facing window. Unfortunately, in the new location I will have access only to west facing window. Why is it good to have some conducting magnetic material under the antenna? Is it to reduce multipath? Best regards, Adam === Adam, Be aware that the signals from the Uputronics board (and similar) are most likely to be at a 3.3V level, which /may/ not be sufficient to drive the DCD pin on a traditional RS232 port, and you may need a level converter. You don't need to connect the other lines - send & receive - just the DCD and ground. I have a simple program which enables you to check for the pulsing of the DCD line (and the other lines too): https://www.satsignal.eu/software/net.htm#SerialPortLEDs Yes, if you can use cgps or similar that would be fine - I just find the phone handier! The puck antennas are designed for use with a ground plane, and the maximum pickup is then at 90 degrees to the ground-plane. I don't think that on these cheap antennas there's any multipath reduction, just more gain from having the ground plane. Be aware that in the new location the glass may have some attenuation at 1.5 GHz as used by GPS. Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
Adam Kumiszcza writes: >> The key here is to have some conducting magnetic material under the >> antenna, not just sitting on its own. > > My GPS antenna hangs on the window handle and still gives the good result. > It's on the south facing window. Unfortunately, in the new location I will > have access only to west facing window. You should orient it correctly so that it is facing up, not simply dangling it from the cable. GPS antennas are directional. > Why is it good to have some conducting magnetic material under the antenna? > Is it to reduce multipath? The GPS dielectric patch antennas are designed to perform best with a ground plane. The optimum size varies a bit, but between 10…14cm in diameter is about right. The ground plane does normally not need to connect to anything, it has to be conductive but not necessarily magnetic (aluminum foil is OK, too). If you have a magnetic puck antenna, then using a magnetic surface has the advantage of the antenna staying in place more easily, though (try the bottom of a large can of vegetables). If you are unsure how large your ground plane really needs to be, just use one of the programs that visualize the signal strength on each sat in view and optimize for highest level over the visible part of the sky, but especially the higher elevations (sats directly above you). Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ Wavetables for the Waldorf Blofeld: http://Synth.Stromeko.net/Downloads.html#BlofeldUserWavetables ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
From: Didier Juges It is my understanding that the latest version of the RPi (Pi4) has a native full speed Ethernet interface, not through USB. I also read that it needs a heat sink. Didier KO4BB Didier, It actually has a gigabit Ethernet, not connected over USB. https://www.raspberrypi.org/magpi/raspberry-pi-4-specs-benchmarks/ The RPi-4 doesn't "need" a heatsink. It's design is intended to provide high-performance bursts to improve the perceived speed - i.e. to create a better user experience. It has throttling if the CPU temperature gets too high, but it you need to run it continuously at full speed then you may need a fan. A number of fans are available, for example: https://shop.pimoroni.com/products/fan-shim https://blog.pimoroni.com/raspberry-pi-4-thermals-and-fan-shim/ 73, David GM8ARV -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Fri, Aug 9, 2019 at 6:04 PM David J Taylor via time-nuts < time-nuts@lists.febo.com> wrote: > You already have a PPS signal from your existing GPS, so I was thinking > simply of distributing that the the Windows PCs, and feeding it to the > serial port's DCD signal. > I will try that. I guess you can connect serial port directly to my Uputronics expansion card ( https://store.uputronics.com/index.php?route=product/product=60_64_id=81) while still attached to Raspberry Pi. Problem is, I'm a software, not a hardware guy. No idea about soldering. Time to learn a new skill :) If the PC doesn't have a serial port, check on the motherboard because > there > are sometimes serial port headers left unconnected by the PC manufacturer. > That's exactly in my case. Motherboard manual says the serial port expansion is sold separately. [..] Check with your Android mobile phone > what the GPS signal levels actually are in your possible locations - I > think > Apple don't allow you to access that information. I don't have access to any Android device :( I'll try to use gpsmon or other tool to check GPS signal level (S/N ratio of satellites should be sufficient, I guess?). > The key here is to have some conducting magnetic material under the > antenna, > not just sitting on its own. My GPS antenna hangs on the window handle and still gives the good result. It's on the south facing window. Unfortunately, in the new location I will have access only to west facing window. Why is it good to have some conducting magnetic material under the antenna? Is it to reduce multipath? Best regards, Adam ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
> > > It is my understanding that the latest version of the RPi (Pi4) has a native full speed Ethernet interface, not through USB. I also read that it needs a heat sink. Didier KO4BB > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Fri, Aug 9, 2019 at 1:01 PM shouldbe q931 wrote: > On Thu, Aug 8, 2019 at 4:07 PM Adam Kumiszcza > wrote: > > Although there is one method using WSL, there is also the "native" method > > https://techcommunity.microsoft.com/t5/Networking-Blog/Top-10-Networking-Features-in-Windows-Server-2019-10-Accurate/ba-p/339739 > "Precision Time Protocol - Try it out!" > Thanks! The link at the bottom is to a .doc file, which gives some explanations. I'll try it out more thoroghly later. ( https://aka.ms/PTPValidation). Some of the required links do not work, though, so it all seems a long way till stable I guess. I have run PTP on a rPi 3B without any kernel modifications as a > grandmaster (with a ublox GPS to provide time and PPS), and experimented > with different NICs (intel, broadcom and solarflare, all with HW > timestamping) as clients in x64 hosts. > What type of PTP did you use? ptpd (https://github.com/ptpd/ptpd) or linuxptp (http://linuxptp.sourceforge.net/)? I've tried the latter, and used the following ntp.conf (part of it here): #PPS Kernel mode server 127.127.22.0 minpoll 4 maxpoll 4 fudge 127.127.22.0 time1 +0.00 flag3 0 refid PPS tos mindist 0.002 #GPS (NMEA) server 127.127.20.0 mode 89 minpoll 4 maxpoll 4 iburst prefer fudge 127.127.20.0 flag1 0 flag3 0 time2 0.059089 refid GPS stratum 2 #local PTP reference server 127.127.28.0 fudge 127.127.28.0 refid PTP /etc/linuxptp/ptp4l.conf has the following lines: clock_servo ntpshm ntpshm_segment 0 priority1 10 priority2 10 (the rest was left as default) /etc/linuxptp/timemaster.conf is as follows: # Configuration file for timemaster [ntp_server localhost] minpoll 4 maxpoll 4 [ptp_domain 0] interfaces eth0 delay 10e-6 [timemaster] ntp_program ntpd [chrony.conf] include /etc/chrony.conf [ntp.conf] includefile /etc/ntp.conf [ptp4l.conf] [chronyd] path /usr/sbin/chronyd [ntpd] path /usr/sbin/ntpd options -u ntp:ntp -g [phc2sys] path /usr/sbin/phc2sys [ptp4l] path /usr/sbin/ptp4l But I think this shows it does not really interact with ntp: pi@zegar:~ $ ntpq -c "cv &3" associd=52436 status=00f1 15 events, clk_no_reply, device="SHM/Shared memory interface", timecode=, poll=1850, noreply=1850, badformat=0, baddata=0, stratum=0, refid=PTP, flags=0 (maybe because there's nothing connected on the other side, but I guess noreply means no reply from PTP daemon?) Best regards, Adam ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
From: Adam Kumiszcza First of all, thank you for the info you put on satsignal.eu org! I've used some of these in the initial configuration of my server. By feeding PPS signal to the Windows PC you mean adding cards or connecting boards (like Sure Electronics GPS evaluation boards) to Windows computers? My idea was to lower the time offset of machines connected by LAN to a single stratum-1 server. But maybe I'll come to that later. Out of your monitored servers on https://www.satsignal.eu/mrtg/performance_ntp.php I am amazed by performance of LeoNTP box. What do you mean by indoor antenna here? Best regards, Adam ___ Adam, One thing - I note you say "single stratum-1 server". With GPS/Raspberry Pi being so cheap, why not have several servers each with a separate antenna? You already have a PPS signal from your existing GPS, so I was thinking simply of distributing that the the Windows PCs, and feeding it to the serial port's DCD signal. If the PC doesn't have a serial port, check on the motherboard because there are sometimes serial port headers left unconnected by the PC manufacturer. If it doesn't have such a header, add a serial port card. If it's a laptop then you might use a serial-over USB connection, but that's likely either not to carry the serial control lines, or be of inferior performance to other methods. LeoNTP - my shack is on the second floor of a UK 2-storey house, and the antenna for the LeoNTP is a magnetic-mount standard puck antenna, mounted on the base of an desk light which is actually on top of a loudspeaker, so the antenna is near the roof but indoors. Check with your Android mobile phone what the GPS signal levels actually are in your possible locations - I think Apple don't allow you to access that information. For this level of performance there's no need for timing antennas. My other GPS antennas are simple on a window sill on a south-facing, second floor window. http://www.satsignal.eu/ntp/2019-01-08-1330-23b-GPS-antenna-farm.jpg The key here is to have some conducting magnetic material under the antenna, not just sitting on its own. There's more about the LeoNTP here: http://www.leobodnar.com/shop/index.php?main_page=product_info_id=272 Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Thu, Aug 8, 2019 at 4:07 PM Adam Kumiszcza wrote: > Hi everybody! My first post here, I hope the subject is adequate for this > mailing list. > > I'm using a tiny layer 1 NTP server consisting of Raspberry Pi 3B+ with > Ublox MAX-M8Q expansion board providing GNSS (currently GPS, Galileo and > Glonass, sometimes I switch to Beidou, too) reference with PPS + a simple > patch antenna hanging near the window. Offset, jitter and rms are most > often smaller than 1 µs. The server is included in NTP pool. > > I'm using several Windows 10 machines on the same LAN, all using NTP client > software from Meinberg. The typical offset and jitter in those are about > 100-500 µs. I would like to make it lower. I've heard that one of the > latest versions of Windows 10 provides support for PTP protocol (IEEE > 1588v2). Hence my questions: > > 1. Did anybody try using it on Windows 10 already? From what I can tell > right now, there's only a demonstration web site showing it works when > using Ubuntu Linux as a virtual machine [1]. Or should I wait a bit for > more robust implementation? > 2. Do I guess correctly that current implementation of PTP works only on > Ethernet? Some of the computers are on wlan. > 3. Is there any other way of making the clients' time offset lower? > Although there is one method using WSL, there is also the "native" method https://techcommunity.microsoft.com/t5/Networking-Blog/Top-10-Networking-Features-in-Windows-Server-2019-10-Accurate/ba-p/339739 "Precision Time Protocol - Try it out!" PTP can be used across any IP network, but if there is non deterministic latency (jitter), there is a fairly obvious effect. The offset should reduce over time, but jitter will affect this. I've already tried setting PTP on the Raspberry Pi 3B+. It needed a kernel > recompilation with a patch I found here: [2], but I'm not sure it works > correctly. > I have run PTP on a rPi 3B without any kernel modifications as a grandmaster (with a ublox GPS to provide time and PPS), and experimented with different NICs (intel, broadcom and solarflare, all with HW timestamping) as clients in x64 hosts. There are two issues with using a rPi as a PTP grandmaster, the crystal is "not very stable", and the NIC is connected over USB, both of these add jitter which is noticeable on PTP. The jjitter is obvious when compared to a meinberg m600 with the HQ OXCO option.connected to a Solarflare NIC in a Linux host. To remove the jitter issues, you might care to try the ublox connected (via a suitable level converter for NMEA and PPS) to a hardware serial port on a Linux X64 host. I have not tried the native Windows PTP client, there are also 3rd party clients from greyware and fsmlabs. > As you can see on the screenshot below, PTP appears here as a server, but > I'm not sure if it's used at all. > [image: status16.PNG] > > Ptp4l status shows this: > > pi@zegar:~ $ systemctl status ptp4l > ● ptp4l.service - Precision Time Protocol (PTP) service >Loaded: loaded (/lib/systemd/system/ptp4l.service; enabled; vendor > preset: enabled) >Active: active (running) since Wed 2019-08-07 12:32:28 CEST; 24h ago > Docs: man:ptp4l > Main PID: 323 (ptp4l) > Tasks: 1 (limit: 4915) >CGroup: /system.slice/ptp4l.service >└─323 /usr/sbin/ptp4l -f /etc/linuxptp/ptp4l.conf -i eth0 > > Aug 07 12:32:31 zegar ptp4l[323]: ptp4l[6.631]: port 1: link up > Aug 07 12:32:31 zegar ptp4l[323]: ptp4l[6.631]: port 1: FAULTY to LISTENING > on FAULT_CLEARED > Aug 07 12:32:31 zegar ptp4l[323]: [6.631] port 1: link up > Aug 07 12:32:31 zegar ptp4l[323]: [6.631] port 1: FAULTY to LISTENING on > FAULT_CLEARED > Aug 07 12:32:38 zegar ptp4l[323]: ptp4l[13.526]: port 1: LISTENING to > MASTER on ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES > Aug 07 12:32:38 zegar ptp4l[323]: ptp4l[13.526]: selected best master clock > b827eb.fffe.006e65 > Aug 07 12:32:38 zegar ptp4l[323]: ptp4l[13.526]: assuming the grand master > role > Aug 07 12:32:38 zegar ptp4l[323]: [13.526] port 1: LISTENING to MASTER on > ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES > Aug 07 12:32:38 zegar ptp4l[323]: [13.526] selected best master clock > b827eb.fffe.006e65 > Aug 07 12:32:38 zegar ptp4l[323]: [13.526] assuming the grand master role > > Thanks in advance for any suggestions! > > Adam Kumiszcza > > [1] > > https://techcommunity.microsoft.com/t5/Networking-Blog/Windows-Subsystem-for-Linux-for-testing-Windows-10-PTP-Client/ba-p/389181 > [2] https://github.com/twteamware/raspberrypi-ptp/issues/2 > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Thu, Aug 8, 2019 at 7:01 PM Tim Lister wrote: > On Thu, Aug 8, 2019 at 8:07 AM Adam Kumiszcza > wrote: > > > > Hi everybody! My first post here, I hope the subject is adequate for this > > mailing list. > > > > I'm using a tiny layer 1 NTP server consisting of Raspberry Pi 3B+ with > > Ublox MAX-M8Q expansion board providing GNSS (currently GPS, Galileo and > > Glonass, sometimes I switch to Beidou, too) reference with PPS + a simple > > patch antenna hanging near the window. Offset, jitter and rms are most > > often smaller than 1 µs. The server is included in NTP pool. > > > > I'm using several Windows 10 machines on the same LAN, all using NTP > client > > software from Meinberg. The typical offset and jitter in those are about > > 100-500 µs. I would like to make it lower. I've heard that one of the > > latest versions of Windows 10 provides support for PTP protocol (IEEE > > 1588v2). Hence my questions: > > > > 1. Did anybody try using it on Windows 10 already? From what I can tell > > right now, there's only a demonstration web site showing it works when > > using Ubuntu Linux as a virtual machine [1]. Or should I wait a bit for > > more robust implementation? > > EndRun Technologies > (https://endruntechnologies.com/products/grandmaster-clocks/ptp-slaves) > make mention of a Windows PTP slave - not sure if it's the same > version you have found. It does also make mention of the fact that > precision is limited on Windows depending on version although from > what I gather from the satsignal.eu that precious on Windows improved > with 7 or later. > It's additional software here. As far as I understand, recent Windows 10 versions introduced under-the-hood internal implementation of PTPv2, with kernel support for it. > > 2. Do I guess correctly that current implementation of PTP works only on > > Ethernet? Some of the computers are on wlan. > > For deterministic timing I think it has to be Ethernet and as outlined > in their white paper (https://endruntechnologies.com/pdf/PTP-1588.pdf) > it works best if you have hardware timestamping in the NICs at each > end and IEEE1588 compatible network switches (and even when the claim > to support it, apparently they don't always do it properly: > > https://www.linkedin.com/pulse/ptp-support-high-end-ethernet-switches-heiko-gerstung > ). > You may be able to do some Pi-to-Windows PTP experiments with a > crossover cable. Not sure if the Pi has the hardware timestamping, > seems unlikely given the low cost of the Pi's as in the 3B+ (and below > I believe) the Ethernet is provided by a combined Ethernet/USB2 hub > and limited by the speed of the USB2. > Pi 3B+ has only software timestamping, and even this is not completely clear (I had to patch the kernel). Pi-to-Windows direct crossover testing is a great idea! Best regards, Adam ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Thu, Aug 8, 2019 at 7:00 PM David J Taylor via time-nuts < time-nuts@lists.febo.com> wrote: > Hi everybody! My first post here, I hope the subject is adequate for this > mailing list. > > I'm using a tiny layer 1 NTP server consisting of Raspberry Pi 3B+ with > Ublox MAX-M8Q expansion board providing GNSS (currently GPS, Galileo and > Glonass, sometimes I switch to Beidou, too) reference with PPS + a simple > patch antenna hanging near the window. Offset, jitter and rms are most > often smaller than 1 µs. The server is included in NTP pool. > > I'm using several Windows 10 machines on the same LAN, all using NTP client > software from Meinberg. The typical offset and jitter in those are about > 100-500 µs. I would like to make it lower. > [] > Thanks in advance for any suggestions! > > Adam Kumiszcza > > > Adam, > > You could feed the PPS signal to the Windows PCs as one way of making the > performance better: > > https://www.satsignal.eu/ntp/setup.html > > Performance: > > https://www.satsignal.eu/mrtg/performance_ntp.php#windows-stratum-1 > > Cheers, > David > First of all, thank you for the info you put on satsignal.eu org! I've used some of these in the initial configuration of my server. By feeding PPS signal to the Windows PC you mean adding cards or connecting boards (like Sure Electronics GPS evaluation boards) to Windows computers? My idea was to lower the time offset of machines connected by LAN to a single stratum-1 server. But maybe I'll come to that later. Out of your monitored servers on https://www.satsignal.eu/mrtg/performance_ntp.php I am amazed by performance of LeoNTP box. What do you mean by indoor antenna here? Best regards, Adam ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
On Thu, Aug 8, 2019 at 8:07 AM Adam Kumiszcza wrote: > > Hi everybody! My first post here, I hope the subject is adequate for this > mailing list. > > I'm using a tiny layer 1 NTP server consisting of Raspberry Pi 3B+ with > Ublox MAX-M8Q expansion board providing GNSS (currently GPS, Galileo and > Glonass, sometimes I switch to Beidou, too) reference with PPS + a simple > patch antenna hanging near the window. Offset, jitter and rms are most > often smaller than 1 µs. The server is included in NTP pool. > > I'm using several Windows 10 machines on the same LAN, all using NTP client > software from Meinberg. The typical offset and jitter in those are about > 100-500 µs. I would like to make it lower. I've heard that one of the > latest versions of Windows 10 provides support for PTP protocol (IEEE > 1588v2). Hence my questions: > > 1. Did anybody try using it on Windows 10 already? From what I can tell > right now, there's only a demonstration web site showing it works when > using Ubuntu Linux as a virtual machine [1]. Or should I wait a bit for > more robust implementation? EndRun Technologies (https://endruntechnologies.com/products/grandmaster-clocks/ptp-slaves) make mention of a Windows PTP slave - not sure if it's the same version you have found. It does also make mention of the fact that precision is limited on Windows depending on version although from what I gather from the satsignal.eu that precious on Windows improved with 7 or later. > 2. Do I guess correctly that current implementation of PTP works only on > Ethernet? Some of the computers are on wlan. For deterministic timing I think it has to be Ethernet and as outlined in their white paper (https://endruntechnologies.com/pdf/PTP-1588.pdf) it works best if you have hardware timestamping in the NICs at each end and IEEE1588 compatible network switches (and even when the claim to support it, apparently they don't always do it properly: https://www.linkedin.com/pulse/ptp-support-high-end-ethernet-switches-heiko-gerstung). You may be able to do some Pi-to-Windows PTP experiments with a crossover cable. Not sure if the Pi has the hardware timestamping, seems unlikely given the low cost of the Pi's as in the 3B+ (and below I believe) the Ethernet is provided by a combined Ethernet/USB2 hub and limited by the speed of the USB2. > 3. Is there any other way of making the clients' time offset lower? NTP works best if the network delay is symmetric and stable - this would also rule against wlan I'm afraid. > > I've already tried setting PTP on the Raspberry Pi 3B+. It needed a kernel > recompilation with a patch I found here: [2], but I'm not sure it works > correctly. > From what I gather the Linux implementation can be either a slave or act as the "grandmaster" without having to buy an expensive external grandmaster clock (the ones I've seen from e.g. Microsemi, Brandywine, Meinberg etc are of the "Get a quote" variety which tends to mean "expensive") > > Thanks in advance for any suggestions! > > Adam Kumiszcza > Cheers, Tim ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
Hi everybody! My first post here, I hope the subject is adequate for this mailing list. I'm using a tiny layer 1 NTP server consisting of Raspberry Pi 3B+ with Ublox MAX-M8Q expansion board providing GNSS (currently GPS, Galileo and Glonass, sometimes I switch to Beidou, too) reference with PPS + a simple patch antenna hanging near the window. Offset, jitter and rms are most often smaller than 1 µs. The server is included in NTP pool. I'm using several Windows 10 machines on the same LAN, all using NTP client software from Meinberg. The typical offset and jitter in those are about 100-500 µs. I would like to make it lower. [] Thanks in advance for any suggestions! Adam Kumiszcza Adam, You could feed the PPS signal to the Windows PCs as one way of making the performance better: https://www.satsignal.eu/ntp/setup.html Performance: https://www.satsignal.eu/mrtg/performance_ntp.php#windows-stratum-1 Cheers, David -- SatSignal Software - Quality software for you Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Precision Time Protocol – Windows 10 implementation
Hi Adam, I've only ever used hardware PTP servers (and I'm far from an expert), but PTP is pretty sensitive to latency. It's common for PTP to deployed on dedicated networks to help keep jitter to a minimum (I think I remember one place doing it on Infiniband but I might be wrong). The challenge I think you're facing is that although the network card on the Pi 3b+ supports gigabit Ethernet, it's still connected via a USB2 hub. This introduces a *lot* of latency. For many applications (and general use) it doesn't hurt performance too much (you'll still be lucky to push ~330Mb/s through it), but when you care about latency it will cause you problems. I didn't test extensively but on the Pi3 (not b+), I would often see millisecond level latencies. For the WiFi question, well, that has even worse latency than the wired (with a number of other issues introduced) so I don't think you'll get much mileage with it. The Pi isn't bad as an NTP server really, especially if your alternative is a server on the Internet (the uBlox M8Q performs really nicely when compared to the Microsemi S650, an industrial grade GNSS time source), but I reckon you're pushing the envelope with what NTP can do on that hardware, and the Pi just doesn't have the hardware to deliver PTP. I would love to hear differently though! Cheers, Pete - Original Message - From: "Adam Kumiszcza" To: "Discussion of precise time and frequency measurement" Sent: Thursday, 8 August, 2019 19:26:11 Subject: [time-nuts] Precision Time Protocol – Windows 10 implementation Hi everybody! My first post here, I hope the subject is adequate for this mailing list. I'm using a tiny layer 1 NTP server consisting of Raspberry Pi 3B+ with Ublox MAX-M8Q expansion board providing GNSS (currently GPS, Galileo and Glonass, sometimes I switch to Beidou, too) reference with PPS + a simple patch antenna hanging near the window. Offset, jitter and rms are most often smaller than 1 µs. The server is included in NTP pool. I'm using several Windows 10 machines on the same LAN, all using NTP client software from Meinberg. The typical offset and jitter in those are about 100-500 µs. I would like to make it lower. I've heard that one of the latest versions of Windows 10 provides support for PTP protocol (IEEE 1588v2). Hence my questions: 1. Did anybody try using it on Windows 10 already? From what I can tell right now, there's only a demonstration web site showing it works when using Ubuntu Linux as a virtual machine [1]. Or should I wait a bit for more robust implementation? 2. Do I guess correctly that current implementation of PTP works only on Ethernet? Some of the computers are on wlan. 3. Is there any other way of making the clients' time offset lower? I've already tried setting PTP on the Raspberry Pi 3B+. It needed a kernel recompilation with a patch I found here: [2], but I'm not sure it works correctly. As you can see on the screenshot below, PTP appears here as a server, but I'm not sure if it's used at all. [image: status16.PNG] Ptp4l status shows this: pi@zegar:~ $ systemctl status ptp4l ● ptp4l.service - Precision Time Protocol (PTP) service Loaded: loaded (/lib/systemd/system/ptp4l.service; enabled; vendor preset: enabled) Active: active (running) since Wed 2019-08-07 12:32:28 CEST; 24h ago Docs: man:ptp4l Main PID: 323 (ptp4l) Tasks: 1 (limit: 4915) CGroup: /system.slice/ptp4l.service └─323 /usr/sbin/ptp4l -f /etc/linuxptp/ptp4l.conf -i eth0 Aug 07 12:32:31 zegar ptp4l[323]: ptp4l[6.631]: port 1: link up Aug 07 12:32:31 zegar ptp4l[323]: ptp4l[6.631]: port 1: FAULTY to LISTENING on FAULT_CLEARED Aug 07 12:32:31 zegar ptp4l[323]: [6.631] port 1: link up Aug 07 12:32:31 zegar ptp4l[323]: [6.631] port 1: FAULTY to LISTENING on FAULT_CLEARED Aug 07 12:32:38 zegar ptp4l[323]: ptp4l[13.526]: port 1: LISTENING to MASTER on ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES Aug 07 12:32:38 zegar ptp4l[323]: ptp4l[13.526]: selected best master clock b827eb.fffe.006e65 Aug 07 12:32:38 zegar ptp4l[323]: ptp4l[13.526]: assuming the grand master role Aug 07 12:32:38 zegar ptp4l[323]: [13.526] port 1: LISTENING to MASTER on ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES Aug 07 12:32:38 zegar ptp4l[323]: [13.526] selected best master clock b827eb.fffe.006e65 Aug 07 12:32:38 zegar ptp4l[323]: [13.526] assuming the grand master role Thanks in advance for any suggestions! Adam Kumiszcza [1] https://techcommunity.microsoft.com/t5/Networking-Blog/Windows-Subsystem-for-Linux-for-testing-Windows-10-PTP-Client/ba-p/389181 [2] https://github.com/twteamware/raspberrypi-ptp/issues/2 -- This message has been scanned for viruses and dangerous content by E.F.A. Project, and is believed to be clean. Click here to report this message as spam. http://efa.membrey.hk/cgi-bin/learn-msg.cgi?id=7E44F20569.A93C5=8c56258c47d97b759f6153822c804b1a ___ time-nuts mailing list -- time
