[time-nuts] CentOS 7, Motorola GPS receiver and NTP

Chris Albertson albertson.chris at gmail.com
Wed Nov 26 15:08:29 EST 2014

On Wed, Nov 26, 2014 at 10:36 AM, Edesio Costa e Silva <
time-nuts at tardis.net.br> wrote:

> Hello!
> Current version of NTP supports Motorola Oncore and PPS. Take a look at
> http://support.ntp.org/bin/view/Support/ConfiguringMotorolaOncoreRefclocks
> Ed├ęsio
The above is certainly required reading.   But in addition  What I would do
is first set up the NTP server using about 3 or 5 Internet "pool" servers
and make sure your other computers are able to connect.

Next work on connecting the hardware.   Many times you can directly connect
the 5 volt TTL level encode to an RS232 serial port.  They are spec'd for
different voltages but is works most of the time.    To be 100% sure you
need to convert the TL level to the rs232 level.

One place where an error is easy to getting the polarity go the PPS signal
correct.  It you invert it then yo are syncing on the trailing edge, you
want the leading edge.


Chris Albertson
Redondo Beach, California

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