[ntp:questions] general questions regarding ntpd on QNX

Николай Орехов nowhere at mail.ru
Thu May 5 07:20:53 UTC 2011


Hello!  
I’m usingntpd to synchronize some devices on QNX from one on QNX, synced from TSIP. With some simple app based on libntpq I query ntpd and 
get somesome status/offsets information. I need offsets to become about millisecondvery fast after start: 
  
tos mindist1.000 
tinkerpanic 0 stepout 60 
disableauth 
  
server127.127.22.0 maxpoll 4 
fudge127.127.22.0 refid PPS0 
  
server 127.127.8.0mode 10 prefer maxpoll 4 
fudge127.127.8.0 refid TSIP time1 0.08 
  
server10.1.1.11 prefer iburst maxpoll 4 
broadcastclient 
  
* When I loose one ntp source, status become “sync_unspec” immediately, but when I loose PPS/ TSIP it may take 30 minutes to reset it to “sync_unspec”. However they become “unreachable” just fine after 2 minutes when I plug out antenna. So is it an error? 
* Time get’s slewed very slowly. It may take 2-3 hours to remove PPS offset of 20ms. Is it a good situation? Can I speed it up to 5 minutes or so?  
* When I use broadcast scheme offsets and jitters on ntp sources may become >10ms. Are there any differences with polling? 
* Can maxpoll decrease or increase slew time or accuracy?  
  
Thanks,Nickolay Orekhov


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