[ntp:questions] Frequency Errors +500 PPM...

Kit Plummer christopher_plummer at raytheon.com
Fri Feb 4 03:31:31 UTC 2005



Richard B. Gilbert wrote:

> Kit Plummer wrote:
>
>>
>>
>> On Feb 3, 2005, at 3:42 PM, Richard B. Gilbert wrote:
>>
>>> Kit Plummer wrote:
>>>
>>>> FWIW, here is a snip of my ntp.log file:
>>>>
>>>>  3 Feb 10:00:14 ntpd[412]: kernel time sync enabled 0001
>>>>  3 Feb 10:04:33 ntpd[412]: synchronized to GPS_BANC(0), stratum=0
>>>>  3 Feb 10:36:45 ntpd[412]: time reset -0.873229 s
>>>>  3 Feb 10:36:45 ntpd[412]: frequency error -512 PPM exceeds 
>>>> tolerance   500 PPM
>>>>  3 Feb 10:41:02 ntpd[412]: synchronized to GPS_BANC(0), stratum=0
>>>>  3 Feb 11:47:44 ntpd[412]: no servers reachable
>>>>  3 Feb 11:48:49 ntpd[412]: synchronized to GPS_BANC(0), stratum=0
>>>>  3 Feb 12:03:51 ntpd[412]: time reset -0.871702 s
>>>>  3 Feb 12:03:51 ntpd[412]: frequency error -512 PPM exceeds 
>>>> tolerance   500 PPM
>>>>  3 Feb 12:08:09 ntpd[412]: synchronized to GPS_BANC(0), stratum=0
>>>>
>>>> What can I do to control the PPM?  This is a SPARC-based VME 
>>>> board,   getting its clock from a VME-based SYNCCLOCK32 GPS/IRIG card.
>>>>
>>>> TIA,
>>>> Kit
>>>>
>>>> On Feb 3, 2005, at 9:46 AM, Kit Plummer wrote:
>>>>
>>>>> Hey folks,
>>>>>
>>>>> I am having NTP prolbems.  Obviously.  But, I am not sure it is 
>>>>> NTP,   or my reference driver - or hardware for that matter.  The 
>>>>> problem   appears to be related to an extremely high PPM.  Am I 
>>>>> understanding   correctly that this number is derived from 
>>>>> whatever is in the   ntp.drift file?
>>>>>
>>>>> Well, the real problem appears to be a 1 second step - 
>>>>> sporadically.    Though I haven't really been able to prove that 
>>>>> either...it is  just  heresay from a system user.
>>>>>
>>>>> Also,  can someone explain this output from ntpd -d:
>>>>>
>>>>> peer GPS_BANC(0) event 'event_reach' (0x84) status 'unreach, conf, 
>>>>> 1   event, event_reach' (0x8014)
>>>>>
>>>>> If there is some other information I can provide for 
>>>>> troubleshooting   purposes let me know.
>>>>>
>>>>> TIA,
>>>>> Kit
>>>>> --------------------------------------------------------------------- 
>>>>> -- -
>>>>> Kit Plummer
>>>>> Operations Research and System Performance Dept.
>>>>> Raytheon Missile Systems
>>>>>
>>>>> _______________________________________________
>>>>> questions mailing list
>>>>> questions at lists.ntp.isc.org
>>>>> https://lists.ntp.isc.org/mailman/listinfo/questions
>>>>>
>>>>
>>> Please don't "top post".
>>>
>>> Do you encounter this problem if you start ntpd with no drift file 
>>> and  with the clock set to within a few seconds of the correct 
>>> time?   If  you do, the first thing to do is to get the hardware 
>>> fixed.  An error  of 512ppm works out to gaining or losing something 
>>> like 48 seconds per  day!   Now few people will argue that the 
>>> typical undisciplined  computer clock is not a  "POS"  but one that 
>>> is that bad is definitely  broken!
>>>
>>> I've run ntpd on something like thirty different computers 
>>> including  Sun/Solaris/Sparc, Compaq/Solaris/X86, DEC Alpha/VMS and  
>>> Compaq/RedHat/X86 without encountering this error.
>>>
>>> Additional helpful information would include the hardware 
>>> platform,   the operating system and version, and the version of 
>>> ntpd that you are  running.
>>> _______________________________________________
>>> questions mailing list
>>> questions at lists.ntp.isc.org
>>> https://lists.ntp.isc.org/mailman/listinfo/questions
>>>
>>
>> Is this better?  I suppose you don't like inline comments  
>> either...interesting, everyone's got their preferences...
>>
>> Keep in mind that I've hacked the refclock_bancomm.c to work with my  
>> VME-based SYNCCLOCK32 board.  Though I am not thinking that the 
>> driver  is the problem.
>>
>> Another few data points worth mentioning is that the VME chassis is  
>> only on for a short amount of time, maybe 4 hours a day max.  I do 
>> have  similar problems with a development chassis that is connected 
>> all the  time...but, not as severe.
>>
>> The SBC is a Force CPU-56, running Solaris 8.  The NTP version that  
>> I've modified is 1.4.2.
>>
>> Here are a couple of snips of potentially worthy info (sorry for the  
>> length of garbage):
>>
>> <ntp.log>
>> 3 Feb 06:06:35 ntpd[637]: frequency error -512 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 06:10:57 ntpd[637]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 06:10:57 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 06:12:02 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 06:13:08 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 06:14:11 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 06:15:15 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 06:16:18 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 06:17:22 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 06:18:26 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 06:35:30 ntpd[637]: time reset +0.983891 s
>>  3 Feb 06:39:48 ntpd[637]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 07:11:59 ntpd[637]: time reset -1.021094 s
>>  3 Feb 07:11:59 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 07:16:14 ntpd[637]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 07:16:14 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 07:17:20 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 07:18:23 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 07:19:29 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 07:20:33 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 07:21:39 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 07:22:45 ntpd[637]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 07:23:51 ntpd[637]: no servers reachable
>>  3 Feb 07:24:56 ntpd[637]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 07:38:58 ntpd[637]: time reset +0.987694 s
>>  3 Feb 07:38:58 ntpd[637]: frequency error 512 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 07:43:15 ntpd[637]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 07:43:15 ntpd[637]: frequency error 507 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 07:44:19 ntpd[637]: frequency error 506 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 07:45:22 ntpd[637]: frequency error 505 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 07:46:28 ntpd[637]: frequency error 504 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 07:47:34 ntpd[637]: frequency error 503 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 07:48:38 ntpd[637]: frequency error 502 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 07:49:41 ntpd[637]: frequency error 501 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 07:50:45 ntpd[637]: frequency error 500 PPM exceeds tolerance  
>> 500 PPM
>>  3 Feb 08:13:52 ntpd[637]: ntpd exiting on signal 15
>>  3 Feb 08:14:47 ntpd[1844]: ntpd exiting on signal 15
>>  3 Feb 08:19:34 ntpd[191]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 08:19:34 ntpd[191]: time reset -0.395297 s
>>  3 Feb 08:19:34 ntpd[191]: kernel time sync disabled 0041
>>  3 Feb 08:23:49 ntpd[191]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 08:30:29 ntpd[191]: ntpd exiting on signal 15
>>  3 Feb 08:30:31 ntpd[383]: configure: keyword "logconfig=syncall"  
>> unknown, line ignored
>>  3 Feb 08:32:57 ntpd[383]: ntpd exiting on signal 15
>>  3 Feb 08:36:11 ntpd[397]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 08:36:11 ntpd[397]: time reset -0.340365 s
>>  3 Feb 08:36:11 ntpd[397]: kernel time sync disabled 0041
>>  3 Feb 08:40:26 ntpd[397]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 08:51:17 ntpd[397]: time reset -0.349002 s
>>  3 Feb 08:51:17 ntpd[397]: kernel time sync enabled 0001
>>  3 Feb 08:55:37 ntpd[397]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 09:02:36 ntpd[397]: ntpd exiting on signal 15
>>  3 Feb 09:05:29 ntpd[419]: ntpd exiting on signal 15
>>  3 Feb 09:10:20 ntpd[181]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 09:10:20 ntpd[181]: kernel time sync disabled 0041
>>  3 Feb 09:11:25 ntpd[181]: kernel time sync enabled 0001
>>  3 Feb 09:12:06 ntpd[181]: ntpd exiting on signal 15
>>  3 Feb 09:12:07 ntpd[358]: configure: keyword "fileget" unknown, 
>> line  ignored
>>  3 Feb 09:14:36 ntpd[358]: ntpd exiting on signal 15
>>  3 Feb 09:17:53 ntpd[369]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 09:22:08 ntpd[369]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 09:33:54 ntpd[369]: kernel time sync enabled 0001
>>  3 Feb 09:35:27 ntpd[369]: ntpd exiting on signal 15
>>  3 Feb 09:38:39 ntpd[403]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 09:38:40 ntpd[403]: time reset +0.481615 s
>>  3 Feb 09:38:40 ntpd[403]: kernel time sync disabled 0041
>>  3 Feb 09:41:55 ntpd[403]: ntpd exiting on signal 15
>>  3 Feb 09:45:09 ntpd[412]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 09:45:09 ntpd[412]: time reset -0.871878 s
>>  3 Feb 09:49:24 ntpd[412]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 10:00:14 ntpd[412]: time reset +0.128403 s
>>  3 Feb 10:00:14 ntpd[412]: kernel time sync enabled 0001
>>  3 Feb 10:04:33 ntpd[412]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 10:36:45 ntpd[412]: time reset -0.873229 s
>>  3 Feb 10:36:45 ntpd[412]: frequency error -512 PPM exceeds 
>> tolerance  500 PPM
>>  3 Feb 10:41:02 ntpd[412]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 11:47:44 ntpd[412]: no servers reachable
>>  3 Feb 11:48:49 ntpd[412]: synchronized to GPS_BANC(0), stratum=0
>>  3 Feb 12:03:51 ntpd[412]: time reset -0.871702 s
>> </ntp.log>
>>
>> Around 8:00 AM I deleted the ntp.drift file...thus the improvement.
>>
>> <server ntpd output>
>> clock_update: at 19299 assoc 1
>> local_clock: assocID 49204 offset -0.872882728 jitter 0.924624933 
>> state  4
>> auth_agekeys: at 19320 keys 1 expired 0
>> refclock_transmit: at 19362 127.127.16.0
>> pp:  34 22:04:38.000934 0
>> refclock_receive: at 19362 127.127.16.0
>
>
> <snip>
>
> The server output doesn't tell me very much!
>
> NTP "1.4.2" is either a typo or a version fifteen or sixteen years 
> old!!!!!  Did you mean 4.2.1?
>
> Have you checked the SYNCCLOCK32 for proper operation?  It's not a 
> clock I'm familiar with.
>
> If you try to synchronize to a public network server, do you still get 
> the error?   If you  can synch to a network server but not to your 
> refclock, I suspect a hardware problem with the refclock.
> _______________________________________________
> questions mailing list
> questions at lists.ntp.isc.org
> https://lists.ntp.isc.org/mailman/listinfo/questions


Yep, a typo.  The server version is actually 4.2.0.  That's a good 
idea...we have a network time server in a box...I'll just point the 
stuff back over at it and see what happens.  I am going to look closer 
at the reference clock...It is definitely an older board.  The maker is 
Brandywine I think.

Kit



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