Re: [ntp:questions] Ntpq.exe memory issue with windows 2019
Am 21.10.20 um 22:45 schrieb David Woolley: > One wild thought: is ntpq or one of its DLLs not position independent > code? I could speculate as to why Windows might keep relocated pages > around in case the code is reloaded at the same address before the page > gets reused for other reasons. However, I don't actually know if > Windows does something like that. That does not jibe with "creeping increase of memory taken". If Win keeps something for reuse ... it should not grow but be reused later again kept for ... :-) Windows has always been a rather buggy and unrealiable OS. Uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Local Time NTP Server
Am 24.08.2020 um 12:51 schrieb Beth Connell: Hi, I'm struggling to find any information on where the free NTP servers are geographically based. In particular, I'm wondering where Facebook, Google, Microsoft, etc are based within the UK. Just for curiousity, I'm wondering how this affects any interference to my location. Thanks The traceroute tool should give you an incling about location. ( if route tracing is allowed and the routers names resolve. often provider routers have geo identifiers: Forex: traceroute to time-a-g.nist.gov (129.6.15.28), 30 hops max, 40 byte packets using UDP 1 zzz.box (182.168.179.1) 0.277 ms 0.345 ms 0.256 ms 2 p3e9bf135.dip0.t-ipconnect.de (62.155.241.53) 20.464 ms 20.144 ms 20.726 ms 3 f-eh1-i.F.DE.NET.DTAG.DE (62.154.18.70) 30.226 ms 29.796 ms 29.851 ms 4 * * * 5 * * * 6 CenturyLink-level3-NewYork6.Level3.net (4.68.70.50) 119.547 ms 118.809 ms 118.944 ms 7 dca-edge-22.inet.qwest.net (67.14.6.142) 119.632 ms 119.404 ms 119.341 ms 8 204.98.157.238 (204.98.157.238) 123.446 ms 122.953 ms 124.012 ms doesn't work as well as it used to work. Uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] create charts
Am 21.08.2020 um 18:49 schrieb William Unruh: On 2020-08-21, David Woolley wrote: On 21/08/2020 11:39, thimoo...@gmail.com wrote: I have a question. how do you make a graph of your ntp server and is that possible What parameter do you want to represent? Remember that the actual error from true time is never known, because, if it could be known, it could be made to be zero. He of course has not told us what he wants to graph, or what his problem is in trying to do so. He cannot "make a graph of your server", since about the only thing accessible to him is time reported by the server Without some other time standard (gpstime, his own computer, some other server,etc) there is nothing to plot. Anybody else getting "request received" from TheFork and a bunch of "undeliverable" from uscc.net for each posting to comp.protocols.time.ntp ? Uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] create charts
Am 21.08.2020 um 13:01 schrieb thimoo...@gmail.com: Op vrijdag 21 augustus 2020 om 12:52:49 UTC+2 schreef David Taylor: On 21/08/2020 11:39, thimoo...@gmail.com wrote: I have a question. how do you make a graph of your ntp server and is that possible i need a linux version gnuplot is your friend. http://www.gnuplot.info/ beyond the terminal there are a range of graph. toolkit frontends around. Uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpd - gpsd communication
Am 05.06.2020 um 09:53 schrieb ah@***.ru: пятница, 5 июня 2020 г., 10:25:24 UTC+3 пользователь Uwe Klein написал: Am 05.06.2020 um 08:36 schrieb ah@***.ru: This sounds more like bit errors in serial reception. ( i.e errors coming up in all magnitudes.) That is reception via NMEA? do you check the NMEA checksum ( Portion after * afair)? Thank you for response. Yes, that is reception via NMEA. No i didn't check checksum, i think gpsd should check it, am i wrong? I just write to log data from SHM when it's all OK. And try to use this correct log after some time to make ntpd change the time. If you think i do something not correct please tell me, i'll try to do something else can you enable data logging and produce logs from the GPS instances that produce errors? ( all sentences received over some time.) Just from a single sytem. As an alternate take a terminal application configured for 4800baud and for the right serial port and log data via that path. never used gpsd put did my own solution years ago for a special use case: https://wiki.tcl-lang.org/page/NTP+plugin+for+a+detachable+nmea+GPS+source ( one app sources NMEA from the device and reflects that into UDP packets.) the other part is sinking UDP packets and funneling those into NTPD. kind of a primitive gpsd replacement ) Uwe I launched gpspipe -R jn all systems, but it's hard to catch it again. I can be not reproducing for a long time Thank you for your decision - did you write it into SHM ? I will see it asaic SHM :: no. it creates an "active" pty device for ntpd to attach to. For ntpd this looks like a regular serial connection. Uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpd - gpsd communication
Am 05.06.2020 um 00:10 schrieb a...@avtodoria.ru: The typical behaviour in case of time jump is that suddenly we have time in gpspipe jumped forth or back for [some seconds - some years]. This sounds more like bit errors in serial reception. ( i.e errors coming up in all magnitudes.) That is reception via NMEA? do you check the NMEA checksum ( Portion after * afair)? Uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Adjust serial device speed in ACTS refclock driver?
Am 06.10.2014 09:00, schrieb Rob: Rich Wales ri...@richw.org wrote: Unless at least one of the known modem time services supports or requires a very high baud rate, BTW, I'm unconvinced that supporting anything higher than 9600 is really necessary for this application. Using the highest possible communication speed removes one of the delays from the system that causes your time to be so far off. which isn't all that interesting. defined constant offsets are easy to fix, aren#t they? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Explaining Technical Detail to Technically illiterate journalist
Am 19.05.2014 15:07, schrieb Terje Mathisen: tim.james.cl...@gmail.com wrote: Hi all, I'm sorry if this post contravenes all guidelines for the group, but I am in Melbourne, Australia and I am writing a non-technical feature story about network time synchronisation (and its usage in everyday applications). I would love to be able to talk to someone (whether via email or instant messenger) about NTC, so that I can explain the protocol and its usage as a part of my story. If anyone is interested in helping me out, please email me at tim.james.cl...@gmail.com There's lots of people here who can give you a lot more information about NTP than you can possibly want or need. :-) Terje overqualified ;-) cue: Explaining Technical Detail to Technically illiterate journalist imho journos tend to be hopeless in a single track mind way. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Slow convergence loopstats (but nice results)
Martin Burnicki wrote: There are network switches out there which are PTP-aware and also timestamp incoming and outgoing PTP packets to compensate the introduced packet delay in some way, but there are no switches (AFAIK) which can do this with NTP packets, so even if you used hardware time stamping of NTP packets on NTP end nodes the resulting accuracy would still be worse than with PTP. That's too sad. What about an RFC for ntp over ptp ;-? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] GPS Weakness Could Sink Wireless
John Hasler wrote: In any case designers of things like cell towers should no more assume that GPS is always just there than they should assume that electric power is always just there. This is a _basic_ shortcoming in CDMA as designed and in use. ( think of it as the NTSC of mobile phone systems ;-) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] GPS Weakness Could Sink Wireless
John Hasler wrote: I wrote: In any case designers of things like cell towers should no more assume that GPS is always just there than they should assume that electric power is always just there. Uwe writes: This is a _basic_ shortcoming in CDMA as designed and in use. ( think of it as the NTSC of mobile phone systems ;-) But Terje points out above that they use Rb oscillators so short (or medium) term loss of GPS by cell towers is not actually a problem. you still have the higher requirement of syncronicity limiting your design. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Is there something with greater detail on interface besides the manpage?
Harlan Stenn wrote: How much info that NTP would care about would come from DHCP? http://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol#DHCP_options uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Pool returns IPv6 address to IPv4 query
Rob wrote: Brian Utterback brian.utterb...@oracle.com wrote: On 11/19/2013 3:40 PM, Danny Mayer wrote: You should not be using literal IP addresses of either flavor without also setting the AI_NUMERICHOST flag otherwise it tries to do a DNS lookup. That's poorly written code otherwise. Danny Not so. The getaddrinfo function will recognize literal addresses and merely convert them. The point is that for something like ssh or any other network utility, the user is supposed to give a hostname, but in virtually all cases you can give a literal address and the application does not have to treat it differently. If you read the ipng mailing list, you will see that they were trying to make the whole process of writing a network application simpler, with getaddrinfo doing the heavy lifting for all of the major cases. At the same time they were trying to allow applications to work on either IPv4 or IPv6 systems without changing them, or dual stack or any combination. But no matter what they did there were edge cases that needed to work differently. Brian Utterback Well most of it was successfull, I converted an application from the old functions to getaddrinfo/getnameinfo etc, and it really is more convenient to program for. However, what I don't understand is why an IPv6 address does not fit into a struct sockaddr, and why this fact is so badly documented. It took me a lot of time to find why my queried IPv6 addresses were truncated. struct sockaddr was a catch all and you had to also hand the size of the storage into the call. forex: int getpeername(int s, struct sockaddr *name, socklen_t *namelen); if you look into sys/socket.h # define __SOCKADDR_ALLTYPES \ __SOCKADDR_ONETYPE (sockaddr) \ __SOCKADDR_ONETYPE (sockaddr_at) \ __SOCKADDR_ONETYPE (sockaddr_ax25) \ __SOCKADDR_ONETYPE (sockaddr_dl) \ __SOCKADDR_ONETYPE (sockaddr_eon) \ __SOCKADDR_ONETYPE (sockaddr_in) \ __SOCKADDR_ONETYPE (sockaddr_in6) \ __SOCKADDR_ONETYPE (sockaddr_inarp) \ __SOCKADDR_ONETYPE (sockaddr_ipx) \ __SOCKADDR_ONETYPE (sockaddr_iso) \ __SOCKADDR_ONETYPE (sockaddr_ns) \ __SOCKADDR_ONETYPE (sockaddr_un) \ __SOCKADDR_ONETYPE (sockaddr_x25) you'll see that there is a range of possible returns depending on protocol. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Fwd: Re: NTP clients
David Woolley wrote: On 04/11/13 23:26, Nomen Nescio wrote: It will display server list while Javed wanna client list. Please unlearn wanna. It is not an English word. It is possibly even more demanding than the want to or which it is a slang contraction. Moreover, want to is often avoided as being too demanding to be polite. Here it would also need to be conjugated to wannas. In this case, wants would have been suitable. want to from which wanna is derived, would be grammatically wrong. This is something you must have learned; it's not a natural mistake for a non-native speaker. Going after the grammatical laxness of native speakers would be an even more redeeming task, wouldn't it? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Trying to use Dimension 4 time keeper
detha wrote: On Sun, 15 Sep 2013 18:56:26 +0100, David Taylor wrote: On 15/09/2013 18:37, unruh wrote: [] Yes, I saw it. Not sure what the voltages are on the Sure unit -- the direct output of the PPS but I think 5V which is still a bit high. I guess one could put a diode in series with the line to bring it down to 3.3V. I would recommend using a restive divider - perhaps 10K and 4.7K to start with - and monitoring the voltage into the Raspberry Pi. Using resistors provides a current limit, and allows the voltage to get down to zero. If the voltage is well below 3.3V, the upper 4.7 K resistor could be reduced. Best to ask on one of the Raspberry Pi support groups as someone has likely already done the measurements. http://jamesreubenknowles.com/level-shifting-stragety-experments-1741 might be of interest. For converting serial signals it works fine, for PPS where one worries about being 100ns off maybe not so much. A lot of 3.3V logic comes in 5V tolerant. Look up the datasheet. For a resistive divider ( that includes the diode hacks ) you need to compensate the input capacitance i.e. a combined resistive/capacitive divider for good rise and fall times. then use shottky diodes. one variant is to use a reasonably strong pullup to the input supply voltage and a diode ( anode * resistor * input ) pull down on diode cathode ( usually higher current capability from the driver side) for low. High voltage on diode cathode will leave the input to go up by way of the pull up resistor. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Syncing and peering for a multi-continent deployment
John Hasler wrote: unruh writes: But perhaps if the whole gps goes down, or goes bad, we as a society will have bigger problems than our computer clocks. Well, it's run out of a single center by a single agency so things other than a loss of satellites could compromise it. Fortunately there's GLONASS and will soon be Galileo. Does anyone sell a timing receiver with GLONASS capability? Well, you can buy GPS receivers that do NAVSTAR _and_ GLONASS. Triple service receivers are around the corner. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] high jitter on serial gps causes big time offsets
website.read...@gmail.com wrote: On Saturday, April 6, 2013 4:18:33 AM UTC-7, Charles Elliott wrote: I would test the local clock before relying on it for time. In the bad old days, around year 2000, when I first started processing SETI@Home (S@H) work units (WUs), I could actually see that WUs were being processed faster in the cool early morning hours than they were in the hot afternoons. The caveat is that an Intel tech support rep denied that that was possible. There is lots of thermal throttling around. But that does not have any connection to crystal precission. Thermal throttling is about reducing the CPU clock by significant amounts ( 1/nth, n=1..10 ? depending on clock multipliers for full speed.) when the on die temp sensor says CPU too hot. In any case, many others have commented on this list that the timing crystals installed in typical motherboards vary significantly with temperature. If you price timing crystals with guaranteed accuracy you may well believe that they don't install them in typical motherboards; they cost at least as much. I can obtain some precision crystals (+/- 2ppm) for about $8 to $10, so why aren't they being added to the mid-level and up motherboards? for about $8 to $10 That is about the money motherboards sell for from the manufacturer, right ;-? It is disgusting to buy a motherboard, load it with graphics processors, and memory and then find that the whole thing cannot keep time. I consider time keeping THE most neglected component in computer motherboards today. Sure. But the majority of users ( even those with perceived to be time critical applications ) don't think much about hardware features. They tend to think in brand items ( hardware and software ). uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] outlyer / falseticker
E-Mail Sent to this address will be added to the BlackLists wrote: unruh wrote: I am positive that no matter where you live, the television show Survivor has made its appearance. I bet they don't get that in North Korea. even if you get it in your country a dubbed version willl not cary the original meaning. German dubbing of StarTrek forex created a completely different series. And most US series ( original or dubbed ) aren't perceived as a must see and large cultural gain. Actually most of it is dumb jingoistic trash. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] multiple instances of NTP on different interfaces
Rob wrote: Uwe Klein u...@klein-habertwedt.de wrote: Abu Abdullah wrote: On Thu, Mar 7, 2013 at 12:41 AM, E-Mail Sent to this address will be added to the BlackLists Null@blacklist.anitech-systems.invalid wrote: unruh wrote: He has gotten himself totally confused about what his real job and desires are, it seems to me. Perhaps its something like, he needs to provide ntp to the pool due to really high vendor zone useage by his appliances? Still sounds like two machines would be better than one. Both are important for us. I can conclude from all the responses that there is no an out of the box solution for the same. I need to have separate OS (or zone). Look into changeroot prisons. Some (Linux) distributions already run ntpd in a change rooted prison. Should be easy to adapt that to a dual setup. This isolates only the filesystem, not the network sockets. Het described a problem with the sharing of the network sockets. Is there an uncircumventable need to share? I would add a set of IP's to the loopback or link-local interface. Have instance A of ntp use 169.254.0.22 Have instance B of ntp use 169.254.0.44 as access to a common network. voila? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] PPS only configuration
E-Mail Sent to this address will be added to the BlackLists wrote: 123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 hard wrapped at 60/61 chars. ( i.e. in the messages as handed in by MTA ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Using NTP to calibrate sound app
Jeroen Mostert wrote: Don't ask me. Ask the piano tuners. Unless you *are* one, of course. In which case it sounds like you have to educate your fellow practitioners. The string arrangement for a single tone presents three tightly coupled resonators. Two distinct pianos are a lot less tightly coupled for the same tone. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Using NTP to calibrate sound app
no-...@no-place.org wrote: On 28 Jan 2013 17:56:10 GMT, Rob nom...@example.com wrote: In my opinion, when you think a crystal is not accurate enough, relying on single-shot time measurements via radio internet connection will *certainly* not be accurate enough. The protocols used on radio channels are not symmetric, because the topology is not symmetric. (there is a single base station communicating with a number of clients) Typical crystal accuracy is in the same ballpark as what you require. When you see significant differences, it is more likely that the actually used crystal frequency is different from what you are reading from some system information call. Yes, that may be true. Smartphone manufactures, for whatever reason, sometimes design a sound system that delivers 22,150 samples per second when my app requests that more standard 22,050. By the way, this has not been a problem with Apple devices (iPhone/iPad), which all seem to be close enough to nominal without custom calibration. But Android devices and Windows laptops are a different story. Can you modify your software to be rate agnostic/flexible? the samling rate error you show is 4000ppm while crystal deviation should not go beyond 50 .. 100 ppm ( 1 cent should be ~416ppm !?) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Using PPS
David Woolley wrote: David Taylor wrote: I'm used to the Windows implementation of NTP, which doesn't have the same PPS implementation. I guess that the Linux type 20 driver must The Windows implementation of NTP is w32time (although not in its out of hte box configuration). Do you actually mean the reference implementation built for Windows? Isn't w32time _S_NTP based? ( and shows discrete adjustments ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Implementing NTP in a legacy system
andreas.a...@de.transport.bombardier.com wrote: Dear all, I'm rather new to NTP so please forgive me, if my question is trivial. I'm maintaining a legacy system with its own proprietary time synchronisation protocols. Now I want to add a new subsystem which requires a NTP daemon to be available. I have added a gateway device which will be used to run an NTP daemon to provide NTP based time synchronisation to the newly added subsystem. My questions are: 1. I want to use my legacy time synchronisation protocol/mechanism as the reference clock of the NTP daemon on the gateway device. In my limited understanding this means that the NTP daemon on the gateway would become a stratum 1 server, right? Are there ways to easily add new reference clocks in popular implementations like ntpd preferably without setting the system time on the gateway? 2. Is it possible to prevent ntpd on the gateway from setting the system time on the gateway? 3. What are the ramifications in view of this being a certified system? ( just guessing, is this something that has a Bahntechnische Zulassung ? ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Win7: ntpd adjusting time backwards
David Taylor wrote: Glad the stats were of some help, and glad to have had the chat. ages ago I needed to timestamp large datasets from a spectrometer rushing in at 50 .. 100 Sample Sets/s. ( on SYSVR3.5 on a MVME167 System ) One way would have been to sync the system via DCF77 and ntp or similar. This would have presented a significant porting effort. My solution was to sample a GPIO pin attached to the DCF77 signal and insert this information together with the freerunning system uptime variable into my data sets. A utility later extracted the DCF time and synced it to the uptime counter. The only hard requirement was for the uptimecounter to be shortime stable. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Timing issue with Linux and kernel PPS?
David Taylor wrote: Thanks for your reply, Miroslav, but I don't even know what udev is, let alone how to edit it! Sorry, but you are way past my level now. udev is the automatic device instantiator invoked from inside the kernel on demand ( i.e. some device found, some event seen ) look into /etc/udev/rules.d/ what rules do you see? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Timing issue with Linux and kernel PPS?
David Taylor wrote: I wonder whether I should be using 127.127.22.1 rather than .0? probably. but and before: do you have the pps-tools package installed? This guy seems to see your problem: http://blog.retep.org/tag/raspberry-pi/ uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Timing issue with Linux and kernel PPS?
Miroslav Lichvar wrote: On Mon, Nov 19, 2012 at 09:02:12AM +, David Taylor wrote: (1) I get Error: could not load pps_ldisc module: No such file or directory insmod needs full path to the module, it's better to call modprobe pps_ldisc. yup, sorry, my error. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Timing issue with Linux and kernel PPS?
David Taylor wrote: Which part of the article or what keyword should I be looking for? UpFront: haven't played around with the raspberry yet. My understanding was that your /dev/pps0 entry appeared too late. ( instantiated late by udev ) is the module pps-gpio loaded during system startup ? lsmod ... other ref: https://github.com/davidk/adafruit-raspberrypi-linux-pps http://www.raspberrypi.org/phpBB3/viewtopic.php?f=9t=1970 uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Timing issue with Linux and kernel PPS?
David Taylor wrote: On 18/11/2012 09:28, Uwe Klein wrote: David Taylor wrote: Which part of the article or what keyword should I be looking for? UpFront: haven't played around with the raspberry yet. My understanding was that your /dev/pps0 entry appeared too late. ( instantiated late by udev ) is the module pps-gpio loaded during system startup ? lsmod ... other ref: https://github.com/davidk/adafruit-raspberrypi-linux-pps http://www.raspberrypi.org/phpBB3/viewtopic.php?f=9t=1970 uwe Thanks, uwe. I've been using the pages you list as a guide. On a working (with PPS pulses) system: cat /etc/modules contains pps-gpio lsmod shows: pps_ldisc used by: 2 pps_gpio used by: 1 pps_core used by: 4 pps_gpio,pps_ldisc On a system with nothing connected to the PPS: cat /etc/modules contains pps-gpio lsmod shows: pps_gpio used by: 0 pps_core used by: 1 pps_gpio I'm unsure how to interpret the difference, or what pps_ldisc does. what happens if you insmod pps_ldisc into the not ready system? you may need a call to ldattach afterwards: http://net.its.hawaii.edu/network-performance/using-praecis/ grep your way through the udev scripts !? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] why does asterisk still show after the ntp server is shutdown?
Rob wrote: It is not like most people really need that accuracy, but they get specifications that are written up by people who do not understand how hard it is to achieve them on standard computer and network hardware. IMHO those requirements tend to be from people that have a shallow understanding of their problem domain. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] why does asterisk still show after the ntp server is shutdown?
Jun Hu wrote: Hi David You've only lost three of the last 8 samples from that server. --- where do you get that ? the reach value or other ? reach is a shifted bitstream reach = (reach 1 ) | (reached)?1:0) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Enclosure for Sure Electronics GPS board
David Taylor wrote: I have just a hand drill and some files - nothing fancy. I find plastic worse than metal owing to its tendency to crack. Aluminium is rather nice to work. A Fretsaw is my preferred tool for doing cutouts ( and a small drill ). a set of needle files for finishing. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP.POOL.ORG Server is a shadowserver
Rob wrote: Mike S mi...@flatsurface.com wrote: On 10/17/2012 3:04 PM, Rob wrote: Today many ISPs and companies run intrusion detection systems that monitor the traffic and send alerts when there is communication with systems listed as botnet CC servers. So when such a server appears on ntp.pool.org, and a user picks it to sync with, they get stamped as potentially infected by malware and could face disconnection or other forms of quarantine. Clear now? Yes. The problem is that the intrusion detection systems run by many companies and ISPs produce false positives. And another problem is that is is *very difficult* to avoid that. Think about it. A CC server could use port 123 for its communication, support normal NTP operations, register itself to the pool, and for the detection system everything would be normal. But maybe it implements some exotic NTP packet like a readvar that allows the botnet to retrieve its info from the CC server. How is the intrusion detection system supposed to recognize this situation without advance knowledge? This would not lead to false positives. this would lead to false negatives. The problem is that commercial entities are absolutely desinterested and careless beyond their business model. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP.POOL.ORG Server is a shadowserver
Rob wrote: And I think that is very wise. There are many protocols that can be used to hide communication, and it is undoable to analyze all of them to the level where you can be sure it is innocent. False positives ruin trust in a tool. ( crying wolf to often. ) If 99% of your alerts are false positives that tool is worthless. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP.POOL.ORG Server is a shadowserver
sh3120 wrote: Have sites complaining that 72.8.140.222 is showing up on command and control server. After research determined that IP is listed in the NTP.POOL.ORG listing of time servers. Unsure who to report this too to get it off the list. it can b confirmed by going to http://www.threatstop.com/checkip and checking the ip address. Thanks. SH Whatever the opinion of ThreatStop is worth: http://ha.ckers.org/blog/20070917/threatstop-anti-botnet-dns/ just like the blacklist providers that try to rip off smaller domainholders. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] System time changes only on restarting ntpd service and query about iterating through the sources
unruh wrote: On 2012-09-08, Richard B. Gilbert rgilber...@comcast.net wrote: I've never seen such a system. I hope I never do! Who manufactured/distributed this P.O.S??? Intel? I think that the theory might be that in this way the battery will not fall out accidentally, and it usually lasts long enough (5 years or so) that the motherboard will be scrapped anyway. There are enough embedded systems around that just don't have a backup battery or a dedicated rtc at that. One can have a range of oppinions on this ( or better not, there are sufficiently persuasive reasons around to not have that functionality ). uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Can someone please explain how dànké. morphs to xn--dnk-9ka1c. when you plug it into IE or Firefox?
M3 wrote: I suspect this might relate to a simple class of one-dimensional cellular automata with two possible values for each cell (0 or 1), and rules depending on them... but I don't quite understand how they work. Of particular interest was how in IE browser the search term dànké. placed into the address bar morphs to URL http://xn--dnk-9ka1c./; only momentarily but then generates a google search for the term dànké. via the below URL. http://www.google.com/search?q=d%C3%A0nk%C3%A9.sourceid=ie7rls=com.microsoft:en-us:IE-Addressie=oe= What processes govern these morphs? Can someone give me a step by step breakdown? http://en.wikipedia.org/wiki/Internationalized_domain_name ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Visual clock display?
Ralph Aichinger wrote: This might be a stupid question: What is the best way to visually display the current time of the local ntp server? Currently I am using a small program that uses gettimeofday on my Linux host. As I only want about 100 milliseconds precision, I should be fine. But is there a proper way to display the time of a ntp server continuously on the screen (for timing a clock via photo/video)? TIA /ralph http://wiki.tcl.tk/17308 hth uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] GPS/NTP and High Frequency Trading
blu wrote: An interesting article today at The Big Picture: http://www.ritholtz.com/blog/2012/08/could-gps-spoofing-cause-another-flash-crash/ It says GPS throughout the article, but at least some of the time it really means NTP. He. High Frequency Trading is an annihilating black hole on its very own. ( See Knight Capital nixing .5 billion in a lunch break ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP vs RADclock?
unruh wrote: ?? What accurate world view. You read the quote. Oh, and it will take you six months to make it happen-minimum Minimum is word with a well defined meaning. Mine took 5 min. 5 min is less than six months. So, it will not take 6 months minimum. It may take 6 months if you are unlucky. It took me 8 month to push our municipalities administration to change the telco contract for our fire fighting stations phone to send out callerid when phoning out ( to ID versus a texting alarm service ) Die Welt ist kein Ponyhof ;-) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Have Pi, have GPS = low powered NTP server?
Ron Frazier (NTP) wrote: Sent from my Android Acer A500 tablet with bluetooth keyboard and K-9 Mail. The dog ate my eMail ;-) (PS - If you email me and don't get a quick response, don't be concerned. I get about 300 emails per day from alternate energy mailing lists and such. set up filters for sorting your eMail into different folders. ( I'd shoot myself before sifting through .5k of eMails per day.) I'm not asking about how to sort the hardware out, I can handle that I think. Just the opinion from anyone who knows more about Linux(Debian or??) on the ARM cpu, and it's ability in this respect. It's said, that the RasPi, has about the same cpu grunt as a 300MHz Pentium, but I have no way to qualify that statement. If eth goes over USB you introduce significant delay _and_ granularity. USB ( whatever speed) is a polled system! ( 1ms slots afair ) look into how the eth dev is set up. Modern ones tend to have globbed interrupts. i.e. one int for multiple packets. Havock for anything that expects expedient package delivery. CPU omphf should never be a problem. ia32 33MHz system used to run ntp well! uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Have Pi, have GPS = low powered NTP server?
Ron Frazier (NTP) wrote: This is found within dmesg's output, after boot... Serial: AMBA PL011 UART driver dev:f1: ttyAMA0 at MMIO 0x20201000 (irq = 83) is a PL011 rev3 console [ttyAMA0] enabled apropos AMBA PL011 UART : http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0183g/I10746.html uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] YEA! My Sure Electronics GPS just arrived.
DaveB wrote: Ron. To fix wandering com ports in Windows, take a look at:- https://fedorahosted.org/fldigi/wiki/Documentation/HOWTO/Windows_USBSeri al The most irritating issue I found under linux is that most manufacturers of commodity stuff like serial USB adapters don't programm serial numbers into their devices. Having a bunch of serial lines to different physical devices mapped in random is a major bother. ( One solution is to attach them in fixed order to one hub. then attach the hub. ports on one hub always seem to have the same enumeration order ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ARRGH!!! I woke up to a 50 SECOND clock error.
David J Taylor wrote: John Hasler jhas...@newsguy.com wrote in message news:87sjh7mlqs@thumper.dhh.gt.org... David J Taylor writes: But in the UK from Virgin Media I have 30 Mb/s down, 1 Mb/s up. I have been promised an upload speed increase about 18 months ago to 2 Mb/s up, which is more sensible... Such a very high cable download speed is a peak burst speeds on a shared medium. Your sustained performance is not likely to be more than a fraction of it. Speed tests from a number of sites show 30 Mb/s, and that's over several seconds. I downloaded the Windows-8 64-bit ISO recently, and the 3,583,707,136 bytes took 48 minutes, 24 seconds, which I make about 7.4 Mb/s, and the 32-bit ISO was 2,711,396,352 bytes in 27 minutes, so about 13.4 Mb/s. That was without any download accelerator (no multiple connections). Sustained transfer speeds are a moot point. You want to know about chanel delays. In absolute, asymmetricness and variation terms. Regular DSL here has quite large and spread line delays though speed is much higher delay is similar or slightly larger than forex ISDN. PING 87.186.242.38 (87.186.242.38) 56(84) bytes of data. ( my first pingable outside node ) 64 bytes from 87.186.242.38: icmp_seq=1 ttl=254 time=48.3 ms 64 bytes from 87.186.242.38: icmp_seq=2 ttl=254 time=34.3 ms 64 bytes from 87.186.242.38: icmp_seq=3 ttl=254 time=77.4 ms 64 bytes from 87.186.242.38: icmp_seq=4 ttl=254 time=70.8 ms 64 bytes from 87.186.242.38: icmp_seq=5 ttl=254 time=108 ms 64 bytes from 87.186.242.38: icmp_seq=6 ttl=254 time=89.0 ms 64 bytes from 87.186.242.38: icmp_seq=7 ttl=254 time=109 ms 64 bytes from 87.186.242.38: icmp_seq=8 ttl=254 time=64.1 ms 64 bytes from 87.186.242.38: icmp_seq=9 ttl=254 time=76.1 ms 64 bytes from 87.186.242.38: icmp_seq=10 ttl=254 time=145 ms 64 bytes from 87.186.242.38: icmp_seq=11 ttl=254 time=199 ms 64 bytes from 87.186.242.38: icmp_seq=12 ttl=254 time=104 ms 64 bytes from 87.186.242.38: icmp_seq=13 ttl=254 time=247 ms 64 bytes from 87.186.242.38: icmp_seq=14 ttl=254 time=104 ms uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ARRGH!!! I woke up to a 50 SECOND clock error.
David J Taylor wrote: Rob nom...@example.com wrote in message news:slrnjmbdn3.9ce.nom...@xs8.xs4all.nl... Uwe Klein u...@klein-habertwedt.de wrote: Regular DSL here has quite large and spread line delays though speed is much higher delay is similar or slightly larger than forex ISDN. PING 87.186.242.38 (87.186.242.38) 56(84) bytes of data. ( my first pingable outside node ) 64 bytes from 87.186.242.38: icmp_seq=1 ttl=254 time=48.3 ms 64 bytes from 87.186.242.38: icmp_seq=2 ttl=254 time=34.3 ms 64 bytes from 87.186.242.38: icmp_seq=3 ttl=254 time=77.4 ms 64 bytes from 87.186.242.38: icmp_seq=4 ttl=254 time=70.8 ms 64 bytes from 87.186.242.38: icmp_seq=5 ttl=254 time=108 ms 64 bytes from 87.186.242.38: icmp_seq=6 ttl=254 time=89.0 ms 64 bytes from 87.186.242.38: icmp_seq=7 ttl=254 time=109 ms 64 bytes from 87.186.242.38: icmp_seq=8 ttl=254 time=64.1 ms 64 bytes from 87.186.242.38: icmp_seq=9 ttl=254 time=76.1 ms 64 bytes from 87.186.242.38: icmp_seq=10 ttl=254 time=145 ms 64 bytes from 87.186.242.38: icmp_seq=11 ttl=254 time=199 ms 64 bytes from 87.186.242.38: icmp_seq=12 ttl=254 time=104 ms 64 bytes from 87.186.242.38: icmp_seq=13 ttl=254 time=247 ms 64 bytes from 87.186.242.38: icmp_seq=14 ttl=254 time=104 ms Funny network... I can ping the same address over my own DSL and get lower and more stable ping than you do: ping 87.186.242.38 PING 87.186.242.38 (87.186.242.38) 56(84) bytes of data. 64 bytes from 87.186.242.38: icmp_seq=1 ttl=245 time=34.7 ms 64 bytes from 87.186.242.38: icmp_seq=2 ttl=245 time=36.3 ms 64 bytes from 87.186.242.38: icmp_seq=3 ttl=245 time=35.3 ms 64 bytes from 87.186.242.38: icmp_seq=4 ttl=245 time=33.6 ms 64 bytes from 87.186.242.38: icmp_seq=5 ttl=245 time=34.8 ms 64 bytes from 87.186.242.38: icmp_seq=6 ttl=245 time=35.8 ms 64 bytes from 87.186.242.38: icmp_seq=7 ttl=245 time=34.2 ms 64 bytes from 87.186.242.38: icmp_seq=8 ttl=245 time=35.3 ms 64 bytes from 87.186.242.38: icmp_seq=9 ttl=245 time=33.0 ms 64 bytes from 87.186.242.38: icmp_seq=10 ttl=245 time=34.2 ms ^C --- 87.186.242.38 ping statistics --- 10 packets transmitted, 10 received, 0% packet loss, time 9043ms rtt min/avg/max/mdev = 33.069/34.776/36.339/0.943 ms Pinging something local in my provider yields stable pingtimes within 13-14 ms... Maybe your provider still uses old ATM technology between the subscribers and the DSL router, and the network is heavily overbooked. This is, however, not a generic property of DSL. DSL can have stable roundtrip times. .. and from Edinburgh: ping 87.186.242.38 Pinging 87.186.242.38 with 32 bytes of data: Reply from 87.186.242.38: bytes=32 time=43ms TTL=239 Reply from 87.186.242.38: bytes=32 time=44ms TTL=239 Reply from 87.186.242.38: bytes=32 time=46ms TTL=239 Reply from 87.186.242.38: bytes=32 time=50ms TTL=239 Ping statistics for 87.186.242.38: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 43ms, Maximum = 50ms, Average = 45ms That's at 11:07 on a Sunday morning. David Deutsche Telekom. Best speed optimised over 4km of copper wire. The variation were from my daughter using the connection for watching youtube in parallel. ( NAT hidden home network. ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ESR looking for good GPS clocks
unruh wrote: He is suggesting that the on board gps chip have ntp on board, so that your computer timestamps the request, the gps chip then timestamps when that trequest was received and returns it. No gps chip that I know of has an onboard ntp server. So if you want to get a chip fab to make you a special purpose chip which contains a gps receiver and ntp onboard, you could probably do it-- but it might cost a bit more than $100 ieach in lots of 100. All the current GPS chips are rather capable DSP enhanced microcontrollers. Freely programmable. The problem is getting access to sources and the toolchain. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Change poll interval at runtime?
David J Taylor wrote: A C agcarver+...@acarver.net wrote in message news:4f4c0508.2010...@acarver.net... [] Zilog was completely standard on sun4c and sun4m so it's neither case of non-standard nor faulty hardware. It's just different (but standard for the architecture). It also hasn't been fully worked through likely because the much more recent Sun hardware had shifted to other hardware components in an effort to reduce costs. Eventually, of course, Sun switched architectures entirely and the latest Sun hardware has an Intel based design rather than the orignal Sun RISC processor designs. OK, so non-standard architecture (for today), then! The IBM-PC Hardware was quite the regression for the time. The 68k and Z80 Systems had real* and capable IO integrated circuits. The initial TTL bitbang stuff was really limited. Z8035, Z8530, M68851, M68230, .. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] GPS Jammers in Use by Criminals - Warping Time for Fraud Suggested
David Woolley wrote: Jason wrote: So, what would be a characteristic symptom or tell-tale of jamming? Simple jamming, as used to defeat vehicle tracking, would result in the loss of all satellites. Sophisticated jamming, to produce a false time, would, for its target, produce a slow drift in the time, with no alarms, although the signal strength would be higher than usual. Receivers at the limits of jammer range might not be able to get consistent solutions across different satellite combinations, so might alarm for that, and otherwise might behave as for a simple jammer. What kind of deviations (type, magnitude) can I introduce via spoofing WAAS or EGNOS transmissions ? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Creating a multi-minute offset
A C wrote: On 2/22/2012 23:56, David Woolley wrote: A C wrote: Ok, so here's an odd question but I had an amusing thought so I want to know: Is it possible to force a client to synchronize with network servers but also maintain a time offset of several minutes from those servers? If this isn't just a special case of timezones, you would need to modify the OS interface layer of the code to shift the time when reading and writing the system clock, so that the core of ntpd sees the correct time. Yeah, it's not a matter of time zone, it's trying to force an absolute time lag on one machine as part of a simulation. The idea was that the clocks should run at the same speed but one of them needs to be shifted from the other. It was a thought but obviously it doesn't work. I would use gpsd to fudge data. The software is probably lucid enough to introduce an adjustable offset onto what is placed in the shm that is used to forward to ntpd. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Oddities in termination of cable from gps18.
unruh wrote: I have a garmin gps 18 connected to my computer with a long (maybe 15m) cat 5e cable, with the PPS carried on one of the twisted pair. I figured it would be a good idea to terminate the cable with a 100 ohm resistor. One testing this the other day, I notices that the signal level was down at 1V, with a staggered risetime of the pulse. -ie it would exponentially rise, to a little plateau, then rise a bit more. Thinking that I had underestimated the cable impedance ( it is after all a single sided pulse, not a balanced signal) I upped it to 200 ohm. Now the pulse rose to 2V but with a very similar shape to the rise. I finally removed the resistor entirely, and now got a 4.5 V pulse, but the shape of the rising edge remained much the same. I would have expected a much sharper rise, with ringing , but no ringing in evidence. I do not understand this. Clearly the 100 ohm was overdriving the output of the gps, but the cable should have looked like 100 ohm to the pulse anyway (at least at first). The open termination of the line should surely have resulted in much more structure to the pulse. (The scope's input impedance should not have altered things much since that is more like a Mohm.) From this it seems that trying to terminate the line is a mistake, and I do not understand why. Is the 110Ohm twisted pair the only connection to your pps sink ? If you connect one conductor to GND on both sides you just introduce some funny groundloops. i.e. the assymetric source driven transmission line works as a baloon and produces a symmetric signal at the other end. If you short circuit that to gnd on one conductor... uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntp version 4.2.7p257-o
Dave Hart wrote: On Tue, Feb 21, 2012 at 08:12, Michael Tatarinov kuk...@gmail.com wrote: easier :) #!/bin/sh eval `ntpq -c 'rv 0 ss_uptime'` let secs=$(($ss_uptime%60)) ... You get the gold star for using ntpq as it was designed to be used :) So many people screen-scrape human-readable ntpq displays without realizing it's all built on var=value underneath. And completely unsave ( and opaque to boot ) . ( Not that i refrain from using similar constructs on all occasions. but I would prefer a save eval that works inside a limited namespace ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntp version 4.2.7p257-o
Terje Mathisen wrote: I.e. that seems to work, but I haven't found a way for the built-in strftime() to output number of days, so I had to handle that separately. %j ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] how to force NTP to use GPS
semi OT ( either OnTopic or OffTopic ;-): What happens if I kill ntpd during clock slewing ? What happens if I SIGTERM ntpd during clock slewing ? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] need help installing gps with ntp on Linux
Ron Frazier (NTP) wrote: Hi Uwe, Thanks for the note. I've spent most of the day troubleshooting this. Your suggestion to check the error logs helped me find a solution. I found an error by apparmor in the syslog. I'll post the complete procedure to get it working once I've had a chance to write it up. Basically, though, I had to edit the apparmor tunable profile for ntpd to allow ntpd to access /dev/gps1 or /dev/gps5, then restart apparmor, then restart ntpd. Once I did that, the dominos started falling into place. I'm now on my way to having a functional system. apparmor was an issue on SuSE some time ago ( now fixed and there is YAST2 help for adjusting profiles now ). ( I didn't know/think about Ubuntu using apparmor ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] need help installing gps with ntp on Linux
Ron Frazier (NTP) wrote: Hi all, I have recently been posting messages about my experience trying to install a USB GPS and wring out the maximum performance in Windows. Now I need help doing the same thing in Linux. I want to install the GPS using only NTPD if possible, without GPSD, to make my install configuration as close as possible to the way it's set up in Windows. Please let me know if I'm on track or not and why my GPS is not working, if possible. I'm running Ubuntu 11.04 and had already installed NTP version 1.4.2.6.p2 from the Ubuntu Natty repositories. That runs fine, polling from the internet. I plugged in the USB GPS and it appeared as /dev/ttyUSB0. I used the following configuration line to set up the port: From: http://www.satsignal.eu/ntp/Sure-GPS.htm I used: stty -F /dev/ttyUSB0 57600 igncr clocal -echo -ixon Then, I used the following command to set up a symlink to the port: ln -T /dev/ttyUSB0 /dev/gps1 (Actually, I tried gps5 first.) Then, I did cat /dev/gps1 and got the following: ron@asus-k52f-1:/etc$ cat /dev/gps1 $GPZDA,011724.000,11,02,2012,,*54 $GPZDA,011725.000,11,02,2012,,*55 $GPZDA,011726.000,11,02,2012,,*56 $GPZDA,011727.000,11,02,2012,,*57 $GPZDA,011728.000,11,02,2012,,*58 $GPZDA,011729.000,11,02,2012,,*59 $GPZDA,011730.000,11,02,2012,,*51 $GPZDA,011731.000,11,02,2012,,*50 So, I know the port is working and I know the GPS is putting out data. Before editing the ntp.conf file, I stopped the service using: sudo /etc/init.d/ntp stop These are the GPS lines in /etc/ntp.conf: server 127.127.20.1prefer minpoll 3 maxpoll 3 mode 72 fudge 127.127.20.1 time2 0.3000 refid GPS1 last year I played around with the Sure Board. see http://wiki.tcl.tk/28358 for me the mode keyword did not work the way it was supposed.( baudrate wise ) check what the baudrate is after ntp has started. Look in the log : /var/log/messages or /var/log/ntp/* for errors. I am running on SuSE, log destination tend to vary over distributions. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Update NTP on FreeBSD 8.2
David J Taylor wrote: On 2012-02-09, David J Taylor david-tay...@blueyonder.co.uk wrote: I did try a portmaster ntp which seems to be building at least a slightly later version on 4.2.6. Try 'portmaster ntp-devel' -- Steve Kostecke koste...@ntp.org Thanks to Kenyon and yourself for that suggestion, Steve. It worked perfectly. I must say that I was rather surprised to see Perl being recompiled just for the earlier NTP update, though. Everything which would take a few seconds on Windows with Dave Hart's ready-built .EXEs appears to take 15-60 minutes on FreeBSD because of all the recompilations which are involved windows runs on just one platform, badly. The BSDs run on a very wide range of architectures currently only bested by Linux ( afaik ) BSD ports is portability by source distribution. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Update NTP on FreeBSD 8.2
David J Taylor wrote: FYI: bested is not English. only Linux runs on more. http://www.thefreedictionary.com/bested http://dictionary.die.net/bested Windows: runs on ia32 and has been expanded to work on the two 64bit derivatives introducing incompatibilities and cludges to no end. The step is so difficult that a significant amount of commercial software is not ported to support any 64bit derivative. Imho this still stands: http://www.urbandictionary.com/define.php?term=Windows uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] How do you reply to list postings
Kenyon Ralph wrote: On 2012-02-08T09:07:33-, David J Taylor david-tay...@blueyonder.co.uk.invalid wrote: I am unsure why people don't just use NNTP - there are plenty of free servers should your ISP not have a USENET server. Eternal September has already been mentioned. All of the other technical groups I subscribe to use mailing lists. Why run another program (usenet reader) in addition to my mail reader, just for one group? I stopped using usenet at least 10 years ago. It is a size/traffic question IMHO. And the google groups ( former alta vista ) nntp archive used to be accessible for comfortable searches. ( Looks like they have nixed that by way of becoming more mainstream. That said, I still subscribe to a range of groups. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] kernel pps
unruh wrote: On 2012-01-18, Uwe Klein u...@klein-habertwedt.de wrote: google should find the details. We should add them to the wiki. Look at: http://www.linuxquestions.org/linux/answers/Hardware/Microsecond_Precision_From_Garmin_18_LVC_GPS_unit_with_PPS_Signal_And_NTP Thanks Any help? Not really since I really do not want to recompile my kernel. So It looks like a need a kernel 2.6.34 I guess. if you have a module named core_pps this should not be neccesary. what happens if you exec modprobe core_pps ( as root ) ? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] kernel pps
google should find the details. We should add them to the wiki. Look at: http://www.linuxquestions.org/linux/answers/Hardware/Microsecond_Precision_From_Garmin_18_LVC_GPS_unit_with_PPS_Signal_And_NTP Any help? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Kernel PPS programs.
Hal Murray wrote: In article X5nSq.1459$kp5...@newsfe18.iad, unruh un...@invalid.ca writes: Further to my kernel pps problems. I have now managed to get pps-ldisc which is supposed to timestamp the serial port DCD transition interrupt, and the pps_parport. In the case of the latter I was wondering if anyone has any idea of how it works. The on board parallel port interface on old motherboards used the edge transition to signal the interrupt. This would mean that once the routine had serviced the interrupt, no other one would occur until that next edge. However, for the add in parallal cards, they use shareable, level triggered interrupts. Since the input pulse is many ms long, this means that the interrupt keeps triggering about once every usec as long as the ack line is up. Does anyone know if the pps_parport module treats such shareable interrupts correctly? Usually, that sort of hardware has a way to turn off the interrupt. It's something like you write a bit in a register to ACK that interrupt. When the external signal turns off, it clears that bit. The info should be in the fine print if you can get a good data sheet. The interrupt controller works differently. you switch from edge triggered to level triggered. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Kernel PPS programs.
David Woolley wrote: unruh wrote: I suppose I could turn of the interrupts on the card for 500ms then turn them on again to catch the next PPS, but that is a real kludge. In the 1970s, level triggering was the norm. The response to ACK is supposed to be to load another outgoing byte or to turn off interrupts on the card. Using it for an open loop PPS signal is abusing it in a way that only works with edge triggered interrupts. It is not really a 70ties feature but the result of a braindead and cheap design. Zilog and Motorola had well thought out extendable architecured designs while Intel produced bottom scrapings. Interesting that just like Microsoft they essentially won out with below par products. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Kernel PPS programs.
unruh wrote: On 2012-01-21, Uwe Klein u...@klein-habertwedt.de wrote: The interrupt controller works differently. you switch from edge triggered to level triggered. Not sure what you mean by this. http://kernel.org/doc/htmldocs/genericirq.html http://www.google.com/search?q=linux+shared+interrupts+level+edge uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Kernel PPS programs.
unruh wrote: On 2012-01-24, DaveB g8...@uko2.co.uk wrote: In article VUBSq.3384$%x7.3...@newsfe10.iad, un...@invalid.ca says... Usually, that sort of hardware has a way to turn off the interrupt. It's something like you write a bit in a register to ACK that interrupt. When the external signal turns off, it clears that bit. The info should be in the fine print if you can get a good data sheet. I have looked carefully, and can onlyfind a bit for turning off interrupts (which of course does not turn on again). That would be fine if it were edge triggered, but not for level triggered. When you program that I/O bit to turn off interupts on that port, it probably clears a latch too, so that it is ready for the next change in input level to trigger another IRQ. See if you can find some original IBM PC schematics and bios listings on t'interweb somewhere. We all learnt a lot back in the day from them. The problem is that these parallel cards are different from the original parallel cards. There use level triggered interrupts so that they can share interrupts with other devices. The PC parallel used edge triggered interrupts which also were unsharable. A sharable interrupt should allow you to switch off the interrupt until the clear edge occurs, at which point the interrupt should switch on again. Just about all the plugin cards and adapters since then, were designed to behave in much the same way, if not using the same circuitry, just integrated all into one small bit of plastic. Nope. they are not. They use totally different interrupt numbers, Not really significant, is it? and logic. The basic register setup is the same. ( braindead but legacy compatible) I've had my fair share of intercourse with those, though not for pps stuff but for talking fast to external hardware via ECP/EPP. You have extra registers for enhanced modes: ECP EPP and the added DMA support and any ancillary function added. usually 400hex higher than the legacy address. With a PCI card you get an additional PCI to ISA bridge and some adaptive logic to interface ints to the pci logic. forex this chip :ST78C34: http://www.exar.com/Common/Content/Document.ashx?id=163LanguageId=1033 or similar from TI: http://www.ti.com/lit/ds/symlink/tl16pir552.pdf uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Linux, Garmin GPX-18X LVM PPS
Miguel Gonçalves wrote: And once you get it working you will start buying GPS devices to add more NTP servers to your network. It's addicting! My main NTP servers are two ALIX 1D mini-ITX computers that consume only 5W! :-) Where does the local chapter for NTP anonymous meet ;-) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Linux, Garmin GPX-18X LVM PPS
Rick Jones wrote: Uwe Klein u...@klein-habertwedt.de wrote: Where does the local chapter for NTP anonymous meet ;-) By the post clock in the town square or train station no?-) Train station clocks in Germany used to be absolutely fascinating they just ticked on for 58 seconds and did a controlled jump to 0 kicked of via landline by the central clock in Frankfurt. Times gone by: when trains tended to have delays in the dozend second domain. ( And my father got irate when his trains trespassed on the 60 second boundary.) Lets meet in Braunschweig ( the master clock has long ago been moved from Frankfurt to the PTB in Braunschweig.) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP Denial of Service attack 29 November 2011
Rich wrote: Someone is at war with USNO NTP service. They could be students, who knows? But all of the offending addresses traced to Chinese sites. In order to continue to provide NTP to US customers, USNO elected to block Chinese networks at the /8 level whenever we were able to trace the attacks to those networks. me@home # for ip in 220.117.53.67 218.92.115.152 114.40.28.224 218.201.21.194 ; do whois $ip ; done | egrep 'descr:|country:' descr: KOREA TELECOM descr: Network Management Center country:KR country:KR country:KR descr: Korea Telecom country:KR descr: CHINANET jiangsu province network descr: China Telecom descr: A12,Xin-Jie-Kou-Wai Street descr: Beijing 100088 country:CN descr: CHINANET jiangsu province network country:CN country:CN descr: China Mobile Communications Corporation - chongqing country:CN country:cn uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP Denial of Service attack 29 November 2011
Danny Mayer wrote: On 11/30/2011 4:35 AM, Rob wrote: Danny Mayer ma...@ntp.org wrote: On 11/29/2011 4:57 PM, Rich wrote: Isn't that a bit wide a range to block for only 4 IPs? What makes you think any further attacks will come from the same range? Only my 17 years experience at the stratum 1 level. I see little value in providing NTP to Asian Pacific networks from Washington, DC. I agree. Not following the rules of engagement for stratum 1/2 servers can mean you block all NTP traffic from those nodes or issuing occasional KOD packets to those nodes. Yes, sure. But blocking an entire region because of 4 abusers? Yes. In this case they are not following the rules of engagement. Sending packets from another Continent doesn't make a lot of sense in any case. Danny I would be surprised if South Korea and the PRC work together in a DDOS attack. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on embedded Linux with GPRS connection
Terje Mathisen wrote: ( I am thinking about providing a good clock source like http://www.maxim-ic.com/datasheet/index.mvp/id/4627 That's interesting, the spec sheet reads like it is supposed to be a drop-in replacement for the regular CMOS RTC clock on PC motherboards? my understanding. additionally the TXCO property is available in power down mode too. There are other specimen around google for RTC TCXO uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on embedded Linux with GPRS connection
mas...@tlen.pl wrote: I have Linux running on ARM. System has GPRS connection to internet, which is slow and unreliable (sometimes it is very hard to establish it, that's probably GSM operator's fault). How is your system supplied with a clock signal? one system wide source or different crystals? ( I am thinking about providing a good clock source like http://www.maxim-ic.com/datasheet/index.mvp/id/4627 ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on embedded Linux with GPRS connection
mas...@tlen.pl wrote: How is your system supplied with a clock signal? one system wide source or different crystals? ( I am thinking about providing a good clock source like http://www.maxim-ic.com/datasheet/index.mvp/id/4627 ) I have RTC built in ARM and a system clock. Self calibrating RTC is not an option because it eats far too much current. but a TCXO enhanced RTC doesn't see the link you deleted. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] /etc/rc: WARNING: $ntpdate_enable is not set properly - see rc.conf(5)
Martin Burnicki wrote: W. D. wrote: (FreeBSD 8.2 release) On Boot up: /etc/rc: WARNING: $ntpdate_enable is not set properly - see rc.conf(5) In /etc/rc.conf using: ntpdate_enable=NO What's wrong with that? Hm, nothing is wrong, as far as I can see. I'm also running a machine with FreeBSD 8.2 release here, have added that line, rebooted, and there's no such error or warning. Maybe there's a syntax error in an ealier line in your rc.conf file? Martin What about a line like: ntpdate_enable=xyz later in rc.conf? ( or some other included file ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Ntpd in uninterruptible sleep?
A C wrote: On 10/24/2011 16:04, Richard B. Gilbert wrote: 64MB is not a lot of RAM by today's standards. Can you install more for testing purposes? Unfortunately not. There are only four slots and I don't have any sticks larger than 16MB so 64 is it for now. However, for the little that the machine does (it's only job is ntpd and gpsd) I think 64 should be adequate. Heheh, still got my MVME167 with 8MB of RAM running SysVR3.6. Are you using the local machine as X-Display? Can you go down to a nongraphical runstate and work via a remote (telnet) session from another box? If nothing else works kill the wedged process hard to create a core dump? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Ntpd in uninterruptible sleep?
A C wrote: I am not using local graphics. There is no desktop environment in use on this machine at all. In fact there is no monitor on the machine (at least not full time). My Xterm and Xclock are exported to a remote machine. OK I need to wait for the process to stall again. It will take a couple days for that to happen and then I'll try a kill-9 after trying to run a stack trace. A SIGTERM kill managed to stop the ntpd process this time but it never generated core. SIGTERM usually doesn't create a core dump ( SIGKILL neither ;-). ( think of the hassle with all the core files when switching runlevels ;-) you may have to adjust max coresize via ?ulimit? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Ntpd in uninterruptible sleep?
A C wrote: More interesting is that the cpu was pegged until I was able to kill and restart ntpd. Most of the cpu was devoted to ntpd during this locked up period. Simple things like typing at the console were difficult. It would take a few seconds for a keypress to register on the screen. Once ntpd was restarted the system responded normally and the cpu usage dropped to normal levels. This is still version 4.2.6p3. I should probably go ahead and compile the most recently released version but I'm at a loss to understand why it happened. CPU (over)loaded or the system is swapping like mad ? ( I'd think it is swapping? ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] suit against timezone database
unruh wrote: On 2011-10-06, Yan Seiner y...@seiner.com wrote: Just came across this on /. http://yro.slashdot.org/story/11/10/06/1743226/civil-suit-filed-involving-the-time-zone-database ?? It looks to me like a frivolous law suit, but I have not seen the details. Facts cannot be copyright, just expressions of them. (eg IBM vs Phoenix in the PC bios case). Compilations cannot be copyright unless they contain some minimum of creative work. (Just ordering the facts is not creative work ) (Telphone book cases have established that). Anyone can file suit. That does not mean that there is any validity to the claims. Often it is a pay us off, it is cheaper than going to court even if you win. Unfortunately although blackmail is a criminal offense, few jurisdictions are willing to go that route. ref: http://lwn.net/Articles/461955/ If I didn't missunderstand it is all about astrology software and trying to litigate a market cleanup and maybe a bit of ego warfare. argh. wonder when the first creative design proponents start to use OSS software as mudd slinging ammunition. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Questions about joining pool.ntp.org
Greg Hennessy wrote: On 2011-08-28, David J Taylor david-tay...@blueyonder.co.uk.invalid wrote: Don't forget the sideband energy from these digital transmissions, and the below zero signal-to-noise ratio of GPS. I really doubt the signal to noise ratio of GPS is below zero. Below unity I would believe. It is well below 0dB. ahh, here: http://www.northwoodlabs.com/AN101.pdf around -22dB you get a win by correlation with the CA PR pattern (~1000 bits). ( you need better than +6dB S/N afair) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Questions about joining pool.ntp.org
David J Taylor wrote: How does this square with those who claim 4ns from their GPS devices? Pfft. The defining document is rather old I guess. A lot happened in between. ( I looked into GPS in my diploma thesis ~1987 and not much after that ) GPS over time is not a static thing. Space and Ground Segment have changed quite a bit. And most everybody today is working from the Coarse Aquisition signal only with precission attributed initially to the P/Y-Code. And notice that most modern receivers have channels galore. What happens if you resolve time from a massively overdetermined setup? ( today you see and work on 10..16 sats at any time ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Questions about joining pool.ntp.org
Chris Albertson wrote: I'm (very slowly) working on a project at home to compare WWV and GPS. The purpose is to measure the ionosphere. Lag in the WWV signal can tell you about radio propagation. Same for the DCF77 timesource in Europe. OT: recently read an article about using GPS receive quality to measure athmospheric changes ( here: effects from NK nuclear subsurface tests ) http://science.slashdot.org/story/11/08/26/1543243/Using-GPS-To-Detect-Secret-Nuclear-Tests uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Fwd: Re: NetBSD GPS/PPS using 4.2.6p3
A C wrote: I will try to capture the outgoing serial data sometime either this weekend or the next when I have a bit more time. I'll send it along to the list as soon as I do. For now I'll leave things using PPS only and see how it works. But I still want to eventually get the GPS refclock working along with PPS just to have a backup clock for network outages. Ok, so I've spliced up a serial tap cable to snoop on the data heading out towards the GPS. Unfortunately I can't seem to decode it. No amount of changing baud rates, stop bits and parity seems to show me anything but a stream of unreadable binary data. It seems to be coming out at 4800 baud although stty says the output speed of the port is 9600. The data seems to have a regular pattern to it with a few of the bytes changing. If anyone can think of a utility that will attempt to autosync to the data I'm open to suggestions. Otherwise I can try to capture the raw data if anyone wants to look at it. Either way, it only transmits while ntpd is using the port. If ntpd is shut down the data stops. Can you access the output strings via a debugger? i.e. trace writes on the port for that process? Much easier to get an idea what is actually sent. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Fwd: Re: NetBSD GPS/PPS using 4.2.6p3
David J Taylor wrote: David Lord sn...@lordynet.org wrote in message news:cm5ki8-m67@p4x2400c.home.lordynet.org... [] From type 20 driver reference: Generic NMEA driver sends a $PMOTG,RMC,*IDcrlf command each poll interval? I noticed that when I wrote my reconnectable plugin. What is it actually there for? ( Sending the same command again and again. Not the config change as such ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Fwd: Re: NetBSD GPS/PPS using 4.2.6p3
Link, Ken wrote: I run 4.2.6p3 with a Sure GPS in Linux and driver 20, but do not see an incoming message (to the device) every poll cycle (at all, actually). # basic nmea source, mode: listen to GPRMC sentence, 9600baud: server 127.127.20.1 mode 17 fudge 127.127.20.1 flag1 0 flag2 0 flag3 0 flag4 0 time1 0.7800 tosch:/tmp # tail -f gpsplug.log ::Stat(pty,slave,fd) = 5 ::Stat(pty,slave,name) = /dev/pts/2 ::Stat(pty,spid) = exp4 ::Stat(udp,port) = 616161 Listening on udp port: 26337 # and this is in my log outgoing: $PMOTG,RMC,*1D $PMOTG,RMC,*1D $PMOTG,RMC,*1D $PMOTG,RMC,*1D $PMOTG,RMC,*1D comes in ~60s intervals. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Fwd: Re: NetBSD GPS/PPS using 4.2.6p3
unruh wrote: But from his test, his system is labelling both edges. so he has bounces on the line? either that or rise/falltime is so low and noise so high that receiver hysteris is not sufficient to supress multiple HL/LH changes? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Single GPS/PPS time source gets marked as a falseticker
Rob wrote: The native binary protocol usually has a SPECIFICATION about the time field in the messages (like: it is the current time at the moment the beginning of the message is leaving the receiver). The NMEA protocol has a time of fix, and that tells you nothing about what time it is now. $GPZDA ? imho binary protocols oftentimes add more problems than they solve. more delay != more uncertainty uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntp server specs
John Hasler wrote: David Woolley writes: Cat 5 is at least 100 ohm. 100 ohms +-5 ohms at 100MHz. For 50 ohms parallel two of the pairs. just use one 100 ohms pair. turns per distance tend to be different for each pair. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] questions Digest, Vol 79, Issue 37
Kevin Coulombe wrote: Hi, Indeed, making it 100% secure is impossible. As long as the user control the hardware, there is always a way to crack it. We need to simply make it difficult enough. From the dicussion here, I think SSL is safe if we provide the client certificate. The only missing lego block is where to get the time from (as was pointed out, within a few hours is good enough). After reading your comments, it does seem like overkill to consider NTP for this. I would have prefered to query a server other than our own to have better uptime (Google's for example). Do you guys know a reliable known server that handles the time protocol through SSL? Well except not checking the certificate here: uwe@home:~ wget -S --no-check-certificate https://www.nist.gov --12:44:16-- https://www.nist.gov/ = `index.html.1' Resolving www.nist.gov... 129.6.13.45 Connecting to www.nist.gov|129.6.13.45|:443... connected. WARNING: Certificate verification error for www.nist.gov: unable to get local issuer certificate HTTP request sent, awaiting response... HTTP/1.1 403 Forbidden Date: Mon, 23 May 2011 10:44:17 GMT Server: Apache Content-Length: 202 Keep-Alive: timeout=15, max=100 Connection: Keep-Alive Content-Type: text/html; charset=iso-8859-1 12:44:17 ERROR 403: Forbidden. I suppose NIST, whitehouse.gov and similar sites do reliably have good time. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Ntp not syncing after powerfail of server
M. Giertzsch wrote: But hmm, still it seems to me that the client does not sync when finished booting before the server does. What about that iburst mentioned in my recent post and may it be that I have to be more patient waiting for the next poll (but I waited half an hour). What is your client platform and what ntp-client do you use ? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpd preplug for detachable gps or testing
Rob wrote: Uwe Klein u...@klein-habertwedt.de wrote: Hi, I needed to sync a box to gps/nmea. But GPS and all other incoming nmea messages pass via socket connection into the main app. So I wrote a preplug for ntp that indirects the gps tty into a pty. i.e. the pty behaves like the tty ( with attached gps ) nmea sentences are handed in via udp socket from either another app or via a helper script that opens and reads a real gps device when available. http://wiki.tcl.tk/28358 uwe The usual way of doing this is with the gpsd server. It handles all your GPS devices and provides an API for one or more applications that use the GPS data, plus a shared memory interface to NTP for time sync. Actually not. I get _all_ nmea sentences of the system piped through one socket. the main application munges all of them ( and the majority is AIS stuff). So the easiest way is to just select the RMC messages and forward those to ntp in some way. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
[ntp:questions] ntpd preplug for detachable gps or testing
Hi, I needed to sync a box to gps/nmea. But GPS and all other incoming nmea messages pass via socket connection into the main app. So I wrote a preplug for ntp that indirects the gps tty into a pty. i.e. the pty behaves like the tty ( with attached gps ) nmea sentences are handed in via udp socket from either another app or via a helper script that opens and reads a real gps device when available. http://wiki.tcl.tk/28358 uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpd preplug for detachable gps or testing
DaveB wrote: In article g7haa8-qa6@klein-habertwedt.de, u...@klein-habertwedt.de says... Hi, I needed to sync a box to gps/nmea. But GPS and all other incoming nmea messages pass via socket connection into the main app. So I wrote a preplug for ntp that indirects the gps tty into a pty. i.e. the pty behaves like the tty ( with attached gps ) nmea sentences are handed in via udp socket from either another app or via a helper script that opens and reads a real gps device when available. http://wiki.tcl.tk/28358 uwe Nice A 2 hour hack. the existing shipboard ntp server was 4h off and unfixable. (i.e. the network/connectivity provider felt unable to fix it.) On MS Win platforms (NT and later) Eterlogic's VSPE can do that sort of thing (and lots else too.) http://www.eterlogic.com/Products.VSPE.html The price is also right. Most of their stuff seems to be a line of tcl code or two away ;-) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] How to keep fake time in past/future?
unruh wrote: On 2011-04-30, Chris Albertson albertson.ch...@gmail.com wrote: On Fri, Apr 29, 2011 at 5:02 PM, unruh un...@wormhole.physics.ubc.ca wrote: Can you not just shut off ntp and set the clock back or forward? Ie, do you care in that case if he clock tracks UTC or not? Point is not to be on exact UTC but still to keep a set of computer's clocks all on the same wrong time. What point is that? I still have no idea why the OP wants to do what he claims to want to do. Test a group of computers transition over some year2000 like dateline ? Being able to setup a reproducible environment ? Simulation is everything. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Windows time question.
Terje Mathisen wrote: Depending upon the cut, quartz crystals can be more or less temperature-sensitive, so it is in fact possible to get one that will wander less when the surrounding temperature changes. AT cut at ~10MHz has best performance. A TCXO avoids the problem, as you noted, by having a thermostat-controlled oven which keeps the temperature more or less constant. The most energy-efficient approach is to have a tiny temperature sensor on or near the crystal, then use a sw lookup table to compensate for temperature swings. OCXO Oven Controlled ... TCXO Temperature Comensated ... TCXOs have made quite a rise in the last decade. (you can't use an oven in a demand powered device like GPS or mobile phone ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Sure GPS: Programming it now works
Rick Jones wrote: Uwe Klein u...@klein-habertwedt.de wrote: ( OT: I had looked into GPS attitude compass devices for a potential customer. first seen usage some years ago by Armadillo Aerospace for attitude control exorbitantly expensive 5..10k€. I'd like to have a cheap dual antenna device ) Being a member of the peanut gallery I have no complete idea what that would be, nor whether one or more of the devices mentioned at http://www.altusmetrum.org/TeleMetrum/ might suffice, or if they might be able to make something along those lines, but I'll post it :) rick jones Interesting. Something like these were on my mind: http://www.septentrio.com/products/receivers/polarx2eat-oem http://www.hemispheregps.com/Products/PrecisionProducts/Main/tabid/543/LiveAccId/21970/Default.aspx http://www.ashtech.com/mb-100-3795.kjsp?RH=1272644306596 prices tend to be a bit overboard though. uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Sure GPS: Programming it now works
E-Mail Sent to this address will be added to the BlackLists wrote:
Uwe Klein wrote:
( OT: I had looked into GPS attitude compass devices
for a potential customer.
first seen usage some years ago by Armadillo Aerospace
for attitude control exorbitantly expensive 5..10k€.
I'd like to have a cheap dual antenna device )
GPS for attitude ?
A GPS with an electronic compass could give you a heading,
(even while not moving). As opposed to just a GPS track,
which doesn't take orientation into consideration
{e.g. moving north while facing west}.
However for attitude, I would think accelerometers,
or a gyroscope, would be necessary for six degrees of freedom,
(perhaps in addition to a magnetoresistive sensor).
{e.g. upside down, moving north while facing west}.
gyro is fast but has drift with time ,
accell is fast but has drift over time ( for distance )
and is dependent on .. accelleration and motion
so you should set up a Kalman Filter for all input.
With two antenna you get all attitude axii except
the antennae intersecting axis.
With three all is resolved.
The septentrio system gives max 10Hz update afair.
uwe
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Re: [ntp:questions] Sure GPS: Programming it now works
unruh wrote: I am also quite impressed with the sensitivity. I am sitting inside my office (on the east side of the building with huge trees just outside the window, and am getting timeing lockon.) my lab is on ground floor, 2 storey house, wooden floors, thatched roof. A large shed with tinplated roof starts in the rear of my lab going west. so half my sky is obscured. I see up to 15 sats. ( from the GSV sentence info ) 387 09 3280 10 26895 11 98556 12 191285 13 55958 14 4875 15 uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Sure GPS: Programming it now works
Terje Mathisen wrote: I have tested and verified that at least my Sure board does not allow me to ask for most of the 19 NMEA sentences listed in the 314 command: Turning on all actually resulted in 5 or 6. I'll try again after first setting the board to 38400 baud. (Maybe it only allows those sentences that actually fit inside the output window?) just toggle on one sentence at a time ? uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Sure GPS: Programming it now works
Terje Mathisen wrote: I can try that as well, but it really does seem like this is the full list of what you can get (notice PMTKCHN has room for up to 32 sats!) over the days I see 49 distinct sats ;-) highest satno 02 .. 51 $PMTKCHN,23322,32182,11382,31272,24282,20192,17432,13252,25031,50001,04001,12031 ,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ,0,0,0,0,0,0*44CRLF What I have found though, by trial error, is that my board can run at a little over 3 Hz: I can ask for any update interval from 307 ms and up, so 333 ms is fine. When I ask for 200 ms (5Hz) I get a '2' response, i.e. command was OK but could not be executed. Do you get distinctly different sentences or a rehash? Is that dependent on the buquet of sentences configured or is the device out-timeslotted for extra work? ( OT: I had looked into GPS attitude compass devices for a potential customer. first seen usage some years ago by Armadillo Aerospace for attitude control exorbitantly expensive 5..10k€. I'd like to have a cheap dual antenna device ) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Sure GPS: Programming it now works
unruh wrote: Somewhat more awkward than Terje's program, but it works. I've collected a bit of information http://wiederlinge.de/cgi-bin/lnwiki.cgi/147 and wrote a basic parser script: http://wiederlinge.de/cgi-bin/lnwiki.cgi/150 Terje added some info too. I will add the commands stuff to my script in ~10days. no time now. Feel free to add. G! uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Sure GPS: Programming it now works
Terje Mathisen wrote: BTW, this morning I got 14 sats in the (4!) GSV messages, that's the first time I've seen a GPS with info about more than 12 sats! :-) Terje I've added some info and (tcl)code to http://wiederlinge.de/cgi-bin/lnwiki.cgi/147 ( And thanks for your help. ) Going to insert the sending stuff real soon now ;-) uwe ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
