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Diffstat (limited to 'usr.sbin/xntpd/README.FreeBSD')
| -rw-r--r-- | usr.sbin/xntpd/README.FreeBSD | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/usr.sbin/xntpd/README.FreeBSD b/usr.sbin/xntpd/README.FreeBSD index 437d478..02a2cac 100644 --- a/usr.sbin/xntpd/README.FreeBSD +++ b/usr.sbin/xntpd/README.FreeBSD @@ -8,3 +8,71 @@ in order to make this code exportable. If you have a legal copy of to the AUTHDEFS in Makefile.inc. You can change CLOCKDEFS in the same file to add other reference clocks. + +---------------------------------------------------- +Support for Conrad electronic's "DCF-77 Uhr, Mobil". +---------------------------------------------------- +Conrad electronic in Germany,, Phone (+49) 962230111 (?), sells a gadget +called "DCF77 Uhr, mobil", which is a DCF77 timecode receiver with a +rs-232 interface. The price is around DM130. + 9-pin interface is Order# 97 94 57 66 + 25-pin interface is Order# 97 94 81 66 + +You must define + -DDCF77 -DPPS -DFREEBSD_CONRAD -DDEBUG +when you compile xntpd. You can later remove -DDEBUG, if you feel like it. + +You must also have + options COM_BIDIR +defined in your kernel, and finally the ttyport you intend to use must +have special interrupt vector: + device sio1 at isa? port "IO_COM2" tty irq 3 vector siointrts + ^^^^^^^^^^^^ +connect the radio-clock to the tty port and link it to /dev/refclock-0: + + cd /dev + sh MAKEDEV cua1 + ln -s /dev/cua01 /dev/refclock-0 + +make a directory to gather statistics in: + mkdir /var/tmp/ntp + +Create a /etc/ntp.conf along these lines: + + # DCF77 without PPS + server 127.127.8.20 + # DCF77 with PPS + #server 127.127.8.148 prefer + + driftfile /var/tmp/ntp/ntp.drift + statsdir /var/tmp/ntp + statistics loopstats + statistics peerstats + statistics clockstats + filegen peerstats file peerstats type day enable + filegen loopstats file loopstats type day enable + filegen clockstats file clockstats type day enable + +Try to start it: + comcontrol ttyd1 bidir + tickadj -A + xntpd -d -d -d + +You should see the red LED flash on the receiver every second now. You +may have to experiment a bit with the location, and possibly adjust the +minute variable resistor inside to get a good signal. Be aware, that just +because you see the light flash, is not the same as the signal being +received by the computer. The chip doing the work in the reciver uses +less than 1 micro-ampere, so even if RTS isn't pulled low, it will happily +receive, but be unable to buffer the signal to the rs-232 levels needed. + +You can see what's going on in /var/log/messages, and query the +daemon using xntpdc and ntpq, in particular the "clockvar" command +of ntpq will tell about the clocks healt. + +I live in Slagelse, Denmark, which is ~1000 Km from Mainflingen, yet +I have +/- 2 ms precision from this cheap gadget. If you have a very +stable signal, you can use the 'pps' address instead to improve your +timing. + +Have fun... Poul-Henning Kamp <phk@login.dkuug.dk> |
