[ntp:questions] Bought a GPS receiver--What next?

Brad Knowles brad at stop.mail-abuse.org
Mon Nov 1 20:16:10 UTC 2004


At 1:20 PM -0600 2004-11-01, W. D. wrote:

>>  >  He says that you need to rebuild the kernel, but others
>>  >  say that it's possible to get better accuracy if you don't.
>>  >  What's the real, full story?
>>
>>          For FreeBSD, you do not need to rebuild your kernel, if you want
>>  refclock support in your NTP server.  The kernel should already have
>>  everything you need in this respect.
>
>  OK, how do I implement this?  What should I put in /etc/ntp.conf
>  to activate this?

	You don't.  This has nothing to do with /etc/ntp.conf.

	This has everything to do with building the ntpd binary itself.

>  OK, what is the procedure to build-in Oncore support?  How is
>  refclock_oncore.c integrated into the NTP executable programs?

	The information you need is included in the source tarball you download.

>  I am running:
>
>    version="ntpd 4.2.0 at 1.1161-r Tue Oct  5 23:55:53 CDT 2004 (2)"
>
>  that's the most recent version, yes?  If it's not configured
>  for refclock support, how do I do this?

	You have to rebuild the binary.

>  Also, it is suggested that I need the configuration file:
>
>    /etc/ntp.oncoreX
>
>  What is the format of the file--what are the appropriate
>  commands and settings?  I don't see this documented
>  fully anywhere.

	I'm not sure.  Someone who has more experience with Oncore 
receivers would have to answer these questions.

>  Twiki pages are also inscrutable:
>  http://ntp.isc.org/bin/view/Support/ConfiguringMotorolaOncoreRefclocks

	I can't make much out of this page myself.

>  http://ntp.isc.org/bin/view/Support/ConfiguringNTP
>  http://ntp.isc.org/bin/view/Support/TestingNTPsBehavior
>  http://ntp.isc.org/bin/view/Support/WebOrder

	Before you get into the configuration details, I think you need 
to first look at designing the network of time servers.  See 
<https://ntp.isc.org/bin/view/Support/DesigningYourNTPNetwork>.

>  I guess if I can't get satisfactory answers to these
>  questions, I'll just try to slog through Art Neilson's
>  instructions:
>
>    http://www.wh7n.net/refclock/clock2.php

	It looks to me like these instructions are pretty old.  They talk 
about xntpd, for example.  The date/time stamps on the files are from 
April 2002.

	I don't know how useful they are going to be.

>  Again, does anyone know how talk to this unit to find out my
>  latitude, longitude and elevation?  How many satellites
>  it sees?

	Again, someone else will have to answer these questions.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.



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