I am trying to get an independently clocked SuSE 11.2 machine based on just GPS/PPS. I am using gpsd 2.95 with garmin 17 serial port but also have tried this with globalsat mr350p. gpsd/cgps shows 3D
signal lock. ntpq Ver. 4.2.6p2 *** HERE IS THE PROBLEM/Question *** When I have an outside source, like 0.us.pool.ntp.org or tick.usask.ca, ntp uses the PPS signal perfectly. When I drop the outside source or substitute with 127.127.0.1, NTP x's out my PPS and then GPS (when reach is 177) even though it is a good signal. How can I force ntp to use the PPS signal or at least not drop it? ************************************ clocksource is tsc which seems to work a little better (also tried hpet, same problem) I also tried it with none of the 'restrict' clauses and without 'disable'. clip from ntp.conf: #Must use disable for SuSe since the internal micro-nano timekeeping #conflicts with ntp and causes excess jitter ( > .010 microsec ). disable kernel server 127.127.28.0 minpoll 4 fudge 127.127.28.0 time1 0.290 refid GPS stratum 3 #garmin server 127.127.28.1 minpoll 4 prefer fudge 127.127.28.1 refid PPS server tick.usask.ca iburst #stratum one canada server driftfile /var/lib/ntp/drift/ntp.drift #(has had values from -70 to 13) restrict -6 ::1 restrict 127.0.0.1 restrict default kod nomodify notrap nopeer noquery restrict tick.usask.ca mask 255.255.255.255 nomodify notrap noquery Soon after restart: ra2:# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== +SHM(0) .GPS. 3 l 3 16 3 0.000 14.703 1.701 *SHM(1) .PPS. 0 l 2 16 3 0.000 -119.90 1.930 +tick.usask.ca .GPS. 1 u 7 64 1 92.725 -109.97 3.086 after 12+ HOURS looks good to me: ra2:~> /usr/sbin/ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== xSHM(0) .GPS. 3 l 7 16 377 0.000 108.591 32.540 *SHM(1) .PPS. 0 l 6 16 377 0.000 0.007 0.000 xtick.usask.ca .GPS. 1 u 41 64 377 92.184 6.839 0.316 ra2:~> /usr/sbin/ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== xSHM(0) .GPS. 3 l 2 16 377 0.000 62.204 24.780 *SHM(1) .PPS. 0 l 1 16 377 0.000 0.007 0.000 +tick.usask.ca .GPS. 1 u 3 64 377 92.184 6.839 0.318 ra2:~> /usr/sbin/ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== xSHM(0) .GPS. 3 l 15 16 377 0.000 83.603 17.002 *SHM(1) .PPS. 0 l 14 16 377 0.000 0.009 0.001 xtick.usask.ca .GPS. 1 u 48 64 377 92.184 6.839 0.318 So, to run without external sources I run both without and with localclock: without 127.127.1.0 (SHM (GPS/PPS) only): ra2:# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== xSHM(0) .GPS. 3 l 13 16 177 0.000 122.103 6.617 xSHM(1) .PPS. 0 l 12 16 177 0.000 -0.113 0.153 ra2:# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== xSHM(0) .GPS. 3 l 7 16 377 0.000 112.004 10.735 xSHM(1) .PPS. 0 l 6 16 377 0.000 -0.186 0.018 ra2:# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== xSHM(0) .GPS. 3 l 11 16 377 0.000 23.303 11.474 xSHM(1) .PPS. 0 l 10 16 377 0.000 -114.74 2.993 # With localclock # LCL is unsynchronized server 127.127.1.0 minpoll 8 fudge 127.127.1.0 refid clk_internal stratum 15 ra2:# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== xSHM(0) .GPS. 3 l 11 16 177 0.000 75.604 25.541 *SHM(1) .PPS. 0 l 10 16 177 0.000 -0.119 0.136 LOCAL(0) .clk_. 15 l - 256 0 0.000 0.000 0.000 ra2:# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== xSHM(0) .GPS. 3 l 4 16 377 0.000 67.604 30.856 xSHM(1) .PPS. 0 l 3 16 377 0.000 -0.107 0.124 LOCAL(0) .clk_. 15 l - 256 0 0.000 0.000 0.000 ra2:# ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== xSHM(0) .GPS. 3 l 2 16 377 0.000 58.803 8.170 xSHM(1) .PPS. 0 l 1 16 377 0.000 0.077 0.014 *LOCAL(0) .clk_. 15 l 32 256 7 0.000 0.000 0.000 using ntpd -ddd there are some early lines: select: survivor 127.127.28.1 5.291672 select: survivor 127.127.28.0 8.291827 select: combine offset -0.047243999 jitter 0.000000477 event at 2 SHM(1) 963a 8a sys_peer but then later: select: survivor 127.127.28.0 3.057312 select: combine offset 0.087603614 jitter 0.021384352 event at 97 SHM(0) 961a 8a sys_peer and then no survivors at all: event at 98 0.0.0.0 0418 08 no_sys_peer _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
