EndRun Sonoma N12, Руководство пользователя

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S o n o m a U s e r M a n u a l 20
C H A P T E R T H R E E
21 S o n o m a U s e r M a n u a l
N E T W O R K T I M E P R O T O C O L ( N T P )
Configuring the Sonoma as a Stratum 2 Server
Operating the Sonoma as a Stratum 1 Server is the recommended mode. However, there are times
when Stratum 2 operation is a good strategy:
1. When you want a backup source of time. In this case, Sonoma will operate as a Stratum 1
Server as long as it is locked to the GPS signal. If it loses the signal, then Sonoma will start to drift
away from “perfect” time. Eventually, when it has drifted 10 milliseconds, it reach the unlocked con-
dition and stop serving time on your network. If you have Sonoma configured for Stratum 2 opera-
tion, then it will continue serving time, using another Time Server as its reference. If Sonoma is later
able to acquire lock on the GPS signal again, it will switch back to Stratum 1 operation.
2. When you want your Sonoma to serve accurate time, but you don’t want to use the antenna (for
some reason). In this case, Sonoma can operate solely as a Stratum 2 server, with no antenna con-
nected.
Since there are innumerable ways to configure your network with Stratum 2 servers, specific insruc-
tions for how to do that are beyond the scope of this manual. General instructions on how to edit the
ntp.conf file are below.
Edit ntp.conf File
You must edit the ntp.conf file in order to point your Stratum 2 server at a Stratum 1 server. Edit /etc/
ntp.conf and add your server line(s). (See Appendix C - Helpful Linux Information for information
on a simple editor.) Here is an example:
server 192.168.1.1
Or, if you have set up a domain name server via
netconfig
, here is another example:
server your.timeserver.com
IMPORTANT
Now save the edited file and copy it to the non-volatile flash partition with this command:
cp -p /etc/ntp.conf /boot/etc
Mask Alarm
In Stratum 1 operation an alarm will be indicated when there is a loss of signal or if the antenna is
not connected. For Stratum 2 operation you may not want to see these alarms. You can mask them
(prevent them from showing) by using the console port (serial/network) commands
setsigfltmask
and
setantfltmask
.
Do not remove the server lines for the refclock. Even if your Time Server is not connected to an antenna,
the refclock server lines must remain.