Discussion:
[chrony-users] Chrony and raw DCF receivers?
V10lator
2017-10-25 07:04:29 UTC
Permalink
Hi,
I wanted to setup my own stratum 1 NTP server, so I wired a raw DCF77
receiver (127.127.8.0 mode 5 or 127.127.8.0 mode 6 with ntpd) to a SBC and
tested a bit with ntpd. After some time I decided to give chrony a try as
ntpd had too much shortcomings.

Now chronyc is a complete show stopper as I can't find a way to tell it to
read the DCF77 signal. There are only options for PPS (GPS receivers, I
think). SHM also is no option as the only thing usable with this is
radioclk but that seems to be for ntpd only:

$ apt-get install radioclk
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer
required:
libtomcrypt0 libtommath0 timelimit
Use 'sudo apt autoremove' to remove them.
The following additional packages will be installed:
ntp
Suggested packages:
ntp-doc apparmor
The following packages will be REMOVED:
chrony
The following NEW packages will be installed:
ntp radioclk
0 upgraded, 2 newly installed, 1 to remove and 0 not upgraded.
Need to get 20.4 kB/485 kB of archives.
After this operation, 910 kB of additional disk space will be used.

So how to use chrony with a raw DCF77 receiver? There doesn't seem to be
any info on the net other than
--
To unsubscribe email chrony-users-***@chrony.tuxfamily.org
with "unsubscribe" in the subject.
For help email chrony-users-***@chrony.tuxfamily.org
with "help" in the subject.
Trouble? Email ***@chrony.tuxfamily.org.
Miroslav Lichvar
2017-10-25 07:20:47 UTC
Permalink
Post by V10lator
Now chronyc is a complete show stopper as I can't find a way to tell it to
read the DCF77 signal. There are only options for PPS (GPS receivers, I
think). SHM also is no option as the only thing usable with this is radioclk
radioclk should work with chrony. It uses the SHM protocol and
doesn't care what NTP daemon is reading the measurements it makes.

It seems it is just a packaging bug in the radioclk package that it
depends on ntp (only):
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863070

There is probably a way to force apt-get or dpkg to install the
package without uninstalling chrony.
--
Miroslav Lichvar
--
To unsubscribe email chrony-users-***@chrony.tuxfamily.org
with "unsubscribe" in the subject.
For help email chrony-users-***@chrony.tuxfamily.org
with "help" in the subject.
Trouble? Email ***@chrony.tuxfamily.org.
Bill Unruh
2017-10-25 16:27:18 UTC
Permalink
Post by V10lator
Hi,
I wanted to setup my own stratum 1 NTP server, so I wired a raw DCF77
receiver (127.127.8.0 mode 5 or 127.127.8.0 mode 6 with ntpd) to a SBC and
tested a bit with ntpd. After some time I decided to give chrony a try as
ntpd had too much shortcomings.
Now chronyc is a complete show stopper as I can't find a way to tell it to
read the DCF77 signal. There are only options for PPS (GPS receivers, I
think). SHM also is no option as the only thing usable with this is radioclk
a) you will need some daemon to actually read the dcf77 signal. chronyd (not
chronyc-- that is just a monitoring tool) does not have anything native. I
know that originally when Lichvar took over he implimented a way to use the
ntpd daemons to read the various refclocks and deliver those to chrony, but I
neither remember or ever used that, and it may not have survived.
b) dcf77 is a lousy refclock. It is only good to ms accuracy, because there is
no way to compensate for the travel time of the signal, or the variations in
that travel time produced by the ionosphere/clouds/... You get much better
accuracy from network time signals, or using a cheap gps receiver.
Post by V10lator
$ apt-get install radioclk
Reading package lists... Done
Building dependency tree Reading state information... Done
The following packages were automatically installed and are no longer
libtomcrypt0 libtommath0 timelimit
Use 'sudo apt autoremove' to remove them.
ntp
ntp-doc apparmor
chrony
ntp radioclk
0 upgraded, 2 newly installed, 1 to remove and 0 not upgraded.
Need to get 20.4 kB/485 kB of archives.
After this operation, 910 kB of additional disk space will be used.
You installed ntpd and removed chrony.
Post by V10lator
So how to use chrony with a raw DCF77 receiver? There doesn't seem to be any
info on the net other than
--
with "unsubscribe" in the subject.
with "help" in the subject.
--
To unsubscribe email chrony-users-***@chrony.tuxfamily.org
with "unsubscribe" in the subject.
For help email chrony-users-***@chrony.tuxfamily.org
with "help" in the subject.
Trouble? Email ***@chrony.tuxfamily.org.
Loading...