[ntp:questions] TSIP and PPS can't synchronize after start

Nickolay Orekhov nowhere at mail.ru
Wed Dec 26 13:41:03 UTC 2012


Hello!

I've got a QNX machine with external Trimble TSIP receiver and PPS going
through serial port ( but supplied by another additional driver ).
Here's my config:

# midist  : increased minimal distance for PPS reference clocks ( default
0.001s )
tos mindist 0.128

# panic   : zero to accept initial big shifts ( default 1000s )
# stepout : how many seconds wait before stepping to spike ( default 900s )
# step    : step threshold in seconds ( default 0.128s )
tinker panic 0 stepout 60

# TSIP reference clock
server 127.127.8.2 mode 138 prefer maxpoll 3 true
fudge 127.127.8.2 refid TSIP time1 0.08 stratum 8

Here's ntpq output:

# /usr/sbin/ntpq 10.1.1.210

ntpq> rv
associd=0 status=0018 leap_none, sync_unspec, 1 event, no_sys_peer,
version="ntpd 4.2.7p164 at 1.2483 Mon Sep 10 04:54:12 UTC 2012 (1)",
processor="x86pc", system="QNX/6.5.0", leap=00, stratum=9, precision=-20,
rootdelay=0.000, rootdisp=1284.075, refid=GENERIC(2),
reftime=d4857ad1.534b73e5  Wed, Dec 26 2012 19:32:01.325,
clock=d4857b83.589b9099  Wed, Dec 26 2012 19:34:59.346, peer=0, tc=3,
mintc=3, offset=13.009, frequency=-16.969, sys_jitter=485.290,
clk_jitter=3.690, clk_wander=0.000, last_step=0.000, step_cntr=0

ntpq> pe
     remote           refid      st t when poll reach   delay   offset
 jitter
==============================================================================
xGENERIC(2)      .TSIP.           8 l    4    8  377    0.000  -394.19
459.192
ntpq> ass

ind assid status  conf reach auth condition  last_event cnt
===========================================================
  1 37217  913a   yes   yes  none falsetick    sys_peer  3
ntpq> cv 37217
associd=37217 status=0020 2 events, clk_unspec,
device="Trimble GPS (TSIP) receiver", timecode="\x10M-^B\x02\x10\x03",
poll=30, noreply=0, badformat=0, baddata=1, fudgetime1=80.000, stratum=8,
refid=84.83.73.80, flags=0,
refclock_ppstime="d4857b8a.89b415be  Wed, Dec 26 2012 13:35:06.537",
refclock_time="d4857b89.b8000000  Wed, Dec 26 2012 13:35:05.718",
refclock_status="TIME CODE; PPS; POSITION; (LEAP INDICATION; PPS SIGNAL;
POSITION)",
refclock_format="Trimble TSIP",
refclock_states="*NOMINAL: 00:03:51 (97.46%); ILLEGAL DATE: 00:00:06
(2.53%); running time: 00:03:57",
trimble_version="1.16 (1906/2/2)", trimble_iooptions="00 00 23 00",
trimble_satview="mode: 2D-AUTO, PDOP 0.00, HDOP 0.00, VDOP 0.00, TDOP 0.00,
2 satellites in view: 01, 11",
trimble_receiver_health="doing position fixes",
trimble_status="machine id 0x5a, Superpackets supported", satellites=2
ntpq> rv 37217
associd=37217 status=913a conf, reach, sel_falsetick, 3 events, sys_peer,
srcadr=GENERIC(2), srcport=123, dstadr=127.0.0.1, dstport=123, leap=00,
stratum=8, precision=-20, rootdelay=0.000, rootdisp=0.000, refid=TSIP,
reftime=d4857b89.b8000000  Wed, Dec 26 2012 19:35:05.718,
rec=d4857b8a.53bba453  Wed, Dec 26 2012 19:35:06.327, reach=377,
unreach=0, hmode=3, pmode=4, hpoll=3, ppoll=3, headway=0, flash=00 ok,
keyid=0, ttl=0, offset=-333.209, delay=0.000, dispersion=347.336,
jitter=421.221,
filtdelay=     0.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00,
filtoffset= -333.21 -394.19  275.11 -412.30  364.76 -344.66 -393.18  275.94,
filtdisp=    320.63  377.33  378.43  356.35  437.03  321.96  376.95  379.26

ntpq>

Also here's output from my pps driver:

# cat /dev/pps0
C 1356529006.540260352
C 1356529007.540283136
C 1356529008.540306176
C 1356529009.540329984
C 1356529010.540353792

Here you can see that timestamps are in the middle of the second.
I know that PPS driver is working and if i divide PPS and GPS into two
sources everything is fine. Also GPS without PPS also works fine.
If i restart ntpd in most cases it will be ok.

Please, could you make suggestions on the following questions:

1. Why source is falseticker? I thought that source can become falseticker
only if ntpd has two or more sources declared.
2. Why it can't synchronize in this way ( but works fine with separated
sources and GPS without PPS )

Thanks, Nickolay Orekhov


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