[ntp:questions] Offset Average (Normal)?
Ron Frazier (NTP)
timekeepingntplist at c3energy.com
Tue Mar 13 03:42:56 UTC 2012
On 3/12/2012 9:27 PM, Alby VA wrote:
> On Mar 12, 9:17 pm, Alby VA<alb... at empire.org> wrote:
>> On Mar 12, 7:21 pm, unruh<un... at invalid.ca> wrote:
>>> On 2012-03-12, Alby VA<alb... at empire.org> wrote:
>>>> If your offset is between -400 to +600 ?s (microseconds), would you
>>>> consider that Good, Bad, or Average?
>>>> If it is less than Good, could something be tweaked to improve it?
>>>> ntp.conf changes? cable changes?
>>>> or I'm just SOL?
>>> What operating system? What is your server (network, wristwatch, gps,
>>> pps?) For PPS you should be able to get +- 1us. for a server in Moscow,
>>> +- 1ms.
>>>> assID=0 status=0115 leap_none, sync_atomic, 1 event,
>>>> version="ntpd 4.2.... at 1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)",
>>>> processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1,
>>>> precision=-19, rootdelay=0.000, rootdisp=1.082, refid=PPS,
>>>> reftime=d308de90.7e20860b Mon, Mar 12 2012 16:44:00.492,
>>>> clock=d308dec4.6a2aacac Mon, Mar 12 2012 16:44:52.414, peer=9406,
>>>> mintc=3, offset=0.081, frequency=-24.987, sys_jitter=6.771,
>>>> clk_jitter=0.003, clk_wander=0.004
>> The Stratum 0 devices is SureGPS and its running on FreeBSD as the OS
>> and AMD for the chip.
>> FreeBSD godzilla.empire.org 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue
>> Feb 21 22:13:35 EST 2012 amd64
> My whole setup isn't anything special. SureGPS is modified so you get
> RS232 cable to COM1 on a FreeBSD box. USB providing power. And several
> NIST/USNO servers in ntp.conf for reference.
> remote refid st t when poll reach delay
> offset jitter
> ntp2.usno.navy. .USNO. 1 u 11h 128 0 21.392
> 11.022 0.000
> -ntp0.usno.navy. .USNO. 1 u 512 128 370 25.747
> -0.242 3.378
> +ntp1.usno.navy. .USNO. 1 u 51 128 377 30.361
> -1.445 2.473
> -time-a.nist.gov .ACTS. 1 u 136 128 336 19.894
> 0.582 5.715
> +time-b.nist.gov .ACTS. 1 u 64 128 57 19.100
> -0.948 2.129
> oPPS(0) .PPS. 0 l 13 16 377 0.000
> 0.502 0.153
> *GPS_NMEA(0) .GPSb. 0 l 12 16 377 0.000
> -38.705 13.177
I will preface this comment by saying I could be all wet and off base.
However, are you sure you're getting data from the serial port. When I
plugged my USB based BU-353, my Ubuntu Linux system automatically loaded
a driver and activated the USB port. The BU-353 has a built in Prolific
based serial - USB converter. So, I'm wondering if you're getting your
data from the USB port and not the serial port. You could try plugging
the USB into one of those AC wall adapters with a USB port for power and
not into the PC. If you are getting data through the serial port, I
would raise the baud rate as high as possible without destabilizing the
system to reduce latency.
(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.)
timekeepingdude AT c3energy.com
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