[ntp:questions] Re: FreeBSD 5.3, Oncore UT+ and PPS

Richard B. Gilbert rgilbert88 at comcast.net
Wed Dec 15 04:30:33 UTC 2004


Dennis Spexet wrote:

>"Richard B. Gilbert" <rgilbert88 at comcast.net> wrote in message 
>news:sfmdnRkibpUckSLcRVn-qg at comcast.com...
>  
>
>>Did you create a soft link from /dev/oncore.0 to the serial port you 
>>connected the Oncore to?
>>    
>>
>
>I created softlinks for /dev/oncore.pps.0, /dev/oncore.0 and 
>/dev/oncore.serial.0.  All of them point to /dev/cuaa0.
>
>I didn't see any instructions to do /dev/oncore.0, nor did I see references 
>to it in refclock_oncore.c, but I did it anyway.
>
>Unfortunately, I did not meet with success.  The status line of ntptime 
>still reads "status 0x2001 (PLL, NANO)".
>
>I'm wondering what it is I am missing.  I rebuilt the kernel with the 
>PPS_SYNC option enabled, and I even checked to make sure that PPS_SYNC was 
>defined to 1 in the right places.
>
>-Dennis Spexet, spexet at visi.com 
>
>
>  
>
Sorry, my error!

I'm running an Oncore M12+T on Solaris 8.  These are the links I had to 
create:
sunblok_$ ls -al /dev/oncore*
lrwxrwxrwx   1 root     other         11 Jan 26  2004 /dev/oncore.pps.0 
-> /dev/term/b
lrwxrwxrwx   1 root     other         11 Jan 26  2004 
/dev/oncore.serial.0 -> /dev/term/b

Here's the configuration file I use:
sunblok_$ more /etc/ntp.oncore0
# /etc/ntp.oncore0
#
# Reference Clock configuration for Motorola Oncore M12
#
# Five Choices for MODE
#    (0) ONCORE is preinitialized, don't do anything to change it.
#          nb, DON'T set 0D mode, DON'T set Delay, position...
#    (1) NO RESET, Read Position, delays from data file, lock it in, go 
to 0D mode.
#    (2) NO RESET, Read Delays from data file, do SITE SURVEY to get 
position,
#                  lock this in, go to 0D mode.
#    (3) HARD RESET, Read Position, delays from data file, lock it in, 
go to 0D mode.
#    (4) HARD RESET, Read Delays from data file, do SITE SURVEY to get 
position,
MODE 1
#     NB. If a POSITION is specified in the config file with mode=(2,4) 
[SITE SURVEY]
#         then this position is set as the INITIAL position of the ONCORE.
#         This can reduce the time to first fix.
LAT 39 45.3753          # Positive is North.
LONG -75 04.27187       # Negative is West
HTGPS 18.28 M           # Height in meters.
SHMEM  /var/log/ntpstats/ONCORE.0
TRAIM YES               # May need this if antenna position is suboptimal.

You could use the same; substituting your own lattitude, longitude, and 
height for mine.
The best way to get the info is to plug your Oncore into a PC running 
<obligatory retching noise> Windows and run the Motorola "WinOncore 12" 
program which you can get from Motorola or, maybe, from 
http://www.synergygps.com/.  Tell it to do a "site survey" and wait 
about twelve hours.  You can then read the numbers off the screen and 
plug them into your configuration file.  If you can't or don't want to, 
you can set mode 4 and the Oncore driver will do a site survey.  I don't 
believe it's quite as extensive as the one done by the Motorola program 
but it may be adequate for your needs.  (I've read that the REALLY 
SERIOUS users of GPS use about 30 days worth of data to get their 
position)   The driver will write the results of the site survey to the 
log file from which you can copy it into your configuration file.

You may need to check the PPS output of your Oncore with an oscilloscope 
and make sure that it's actually being generated and that it is actually 
wired to the DCD pin on the serial port you are using.  There's a 
"clktest.c" program in the "clockstuff" subdirectory which may tell you 
something useful; I've never used it myself.

If this all checks out, there may still be a bug or two in the Motorola 
driver.  I needed to get some patches from the driver's maintainer 
before it would even build properly on Solaris 8!  I believe that the 
patches are in "dev" versions more recent than February or March 2004 
but they were not in the 4-2.0 release.

Good luck!



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