[ntp:questions] Doubt about Syncronization of GPS SPECTRACOM(2)

Richard B. gilbert rgilbert88 at comcast.net
Wed Feb 28 21:35:31 UTC 2007


Marcos Onisto wrote:
> Hello All,
> 
> My doubt is about how can I consult my SPECTRACOM(2)? What the correct
> way? I only can consult using the command ntpq or I can use de command
> ntpdate with the serial port (127.127.4.2)? follow below:
> 
<snip>

You can't talk to your Spectracom directly.  Ntpd does that for you.

ntpq -p
Will show you the status of the Spectracom

Like this (this is my reference clock which is a GPS receiver (Motorola 
Oncore))
sunblok_$ ntpq -p
      remote           refid      st t when poll reach   delay   offset 
  jitter
==============================================================================
*GPS_ONCORE(0)   .GPS.            0 l   12   16  377    0.000    0.001 
  0.001
(Internet servers omitted)

This tells me that the Motorola is selected as the synchronization 
source (the "*" in the first column).  It also tells me that ntpd polled 
it 12 seconds ago, that the poll interval is 16 seconds, that the last 
eight poll attempts were successful (the 377), that the round trip delay 
is too small to measure, and that the offset of my local clock from the 
GPS receiver is one microsecond.

Your ntpq banner (copied from an earlier post)
      remote           refid      st t when poll reach   delay   offset 
  jitter
 
==============================================================================
*SPECTRACOM(2)   .WWVB.           0 l   44   64  377    0.000   -0.095 
  0.019

Shows that the Spectracom has been selected as the synchronization 
source, was last polled 44 seconds ago, that the poll interval is 64 
seconds, that the Spectracom responded to the last eight poll attempts, 
that the round trip delay is too small to measure and that the offset of 
your local clock from the Spectracom is 95 microseconds.

It looks good to me!




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