[ntp:questions] Offset Average (Normal)?

Ron Frazier (NTP) timekeepingntplist at c3energy.com
Tue Mar 13 15:42:35 UTC 2012

On 3/13/2012 10:21 AM, Alby VA wrote:
> On Mar 13, 9:59 am, David Lord<sn... at lordynet.org>  wrote:
>> That seems to be working ok.
>> The NMEA sentences aren't being reported because PPS is being
>> used to condition the system clock.
>> David
>   Okay. My whole understanding of NTP and Clocks is now
> becoming clearer. My apologies, I'm still a n00b.
>   So what you are saying is the GPS time via the SureGPS
> device is now being ignored and the time of my machine is
> now being held in check by the PPS signal? If yes, does
> that mean seeing "oGPS_NMEA" is better than seeing
> "*GPS_NMEA"?
>   Since I can't find any docs on deciphering the ntpq output,
> I'm trying to understand what the symbols next to each
> entry represent. Some I've found, but maybe you could
> correct me:
> o = ???
> * = ??? (My Assumption: preferred time server)
> x = ??? (My Assumption: False Tick - Bad Time)
> + = ??? (My Assumption: Next Best Server for Time)
> - = ??? (My Assumption: Ignore this useless server)
> ** Sorry for all the questions. Just trying to educate myself on being
> a
> time master too. :)

Here is where you can find the data on the codes.  I'm a noob too, and 
this info was NOT easy to find, unless you already know where to look, 
which noobs don't.


That second link should take you to the "Peer Status Word" section of 
the page.  Look in the second table in that section under "Select 
Field".  You'll see a short description of the symbols, which they call 
tally codes.

Here's a copy of the table.  Apologies to anyone not viewing this in 
html as it may scramble the table.

Code 	Message 	T 	Description
0 	sel_reject 		discarded as not valid (TEST10-TEST13)
1 	sel_falsetick 	x 	discarded by intersection algorithm
2 	sel_excess 	. 	discarded by table overflow (not used)
3 	sel_outlyer 	- 	discarded by the cluster algorithm
4 	sel_candidate 	+ 	included by the combine algorithm
5 	sel_backup 	# 	backup (more than tos maxclock sources)
6 	sel_sys.peer 	* 	system peer
7 	sel_pps.peer 	o 	PPS peer (when the prefer peer is valid)

Here's some more data.  This is a print screen from the Legend button on 
the Meinberg time server monitor.  I don't know how long this will stay 
in my dropbox, so if you want to keep it, you should save it.


I agree all this can be very confusing.  Hope this helps




(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.  I don't always see new messages very quickly.  If you need a
reply and have not heard from me in 1 - 2 weeks, send your message again.)

Ron Frazier
timekeepingdude AT c3energy.com

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