[LinuxPPS] gps & offset

[Folkert van Heusden]

Hi,

Now that PPS and such finally seem to work I found an other issue: a
large negative offset.
I'm using the same ntp configuration as Udo does with the same garmin 18
lvc:
server 127.127.20.0 prefer minpoll 4
fudge 127.127.20.0 flag3 1 flag2 0 time1 0.000
server 127.127.22.0 minpoll 4 maxpoll 4
fudge 127.127.22.0 flag3 1 flag2 0 time1 0.000

Now after 12 minutes of run-time I see:
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
xGPS_NMEA(0)     .GPS.            0 l    8   16  377    0.000  -188.47   1.789
 PPS(0)          .PPS.            0 l    -   16    0    0.000    0.000   0.001
-muur.intranet.v .DCFa.           1 u   41   64  376    0.010  -11.986   0.564
-thegateap.intra 194.171.167.130  2 u   11   64  336    0.817    0.196   0.959
 SHM(0)          .SHM0.           2 l    -   64    0    0.000    0.000   0.001
 SHM(1)          .SHM1.           2 l    -   64    0    0.000    0.000   0.001
 SHM(2)          .SHM2.           2 l    -   64    0    0.000    0.000   0.001
 SHM(3)          .SHM3.           2 l    -   64    0    0.000    0.000   0.001
 NTP.MCAST.NET   .MCST.          16 u    -   64    0    0.000    0.000   0.001
 192.168.64.0    .BCST.          16 u    -   64    0    0.000    0.000   0.001
-auth1.xs4all.nl 193.79.237.14    2 u    2   64  377    8.630   -1.038   1.022
-auth2.xs4all.nl 193.67.79.202    2 u    1   64  377    8.405   -4.191   0.757
-ntp1.nl.uu.net  .GPS.            1 u   60   64  377   16.834   -0.660   9.992
+chime2.surfnet. .GPS.            1 u   65   64  377   12.216   -1.973   0.312
*chime1.surfnet. .GPS.            1 u   60   64  377    8.866   -2.627   0.769
+194.109.64.200  192.87.106.3     2 u   58   64  377    8.157   -2.230   0.402
-ruumzp.med.uu.n 213.239.154.12   3 u   57   64  377   10.970   -3.603   0.686

An offset of 188ms! That is quiet a bit.
I tried 'flag2 1' as well but that did not help.

Of course I did everything that is written on
http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver20.html

The gps says by the way:
$GPRMC,154017,A,5201.6407,N,00442.2908,E,000.0,154.2,140108,000.9,W*67
$GPRMC,154018,A,5201.6407,N,00442.2908,E,000.0,154.2,140108,000.9,W*68
$GPRMC,154019,A,5201.6407,N,00442.2907,E,000.0,154.2,140108,000.9,W*66
              ^
	    so it should be valid data


Folkert van Heusden

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