[time-nuts] ntpd not talking to gpsd

Matthew Smith matt at smiffytech.com
Wed Apr 2 01:31:21 EDT 2008

Hi Folks

Having laid aside my troublesome Oncore GT+s for the moment, I have 
hooked my VP up to the (soon to be) time server and have run gpsd.

Telnet'ing in, I am able to do this:


For some reason, running -D 5 on my Sun Blade 100, I am not seeing any 
mention of the DCD changing state (logic probe shows that the line is 
getting the 1PPS correctly), although this is working OK on my Linux 
ThinkPad, via a USB to serial adapter.  (And yes, I have made sure that 
the Sun connector uses pin 1 as DCD, just in case anything was being 
done in a non-standard way.)

I set up /etc/ntp.conf (both machines) as advised in the gpsd man page:

server minpoll 4 maxpoll 4
fudge time1 0.420 refid GPS

#server minpoll 4 maxpoll 4 prefer
#fudge refid GPS1

(The second bit was just commented out on the Linux box - the Blade is 
running OpenBSD - in case the Linux kernel didn't understand PPS.)

brutus smith # ntpq -p
remote     refid   st t when poll reach   delay   offset jitter
SHM(0)     .GPS.   0 l    -   16    0    0.000    0.000   0.001

...and ditto for the PPS line on the Blade.  'reach' is always zero. 
gpsd is most certainly running and is getting the time, as per my test 
above (applies to both machines).

What am I missing here?  Do I have to build ntpd from source with extra 
options set or something?  The OpenBSD machine is running ntp-4.2.0ap3 
and the Linux box 4.2.4p4, the one installed via pkg_add, the other from 
the default ebuild.

Time to pull the antenna now - possible storms about.



Matthew Smith
Smiffytech - Technology Consulting & Web Application Development
Business: http://www.smiffytech.com/
Personal: http://www.smiffysplace.com/
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