[ntp:questions] Q: PPS clock's variables: Some look strange

Ulrich Windl Ulrich.Windl at RZ.Uni-Regensburg.DE
Wed Jul 21 07:18:18 UTC 2010


I'm wondering if there's something wrong with the clock variables of a
"PPS clock". Looking aat those, I get:
ntpq> cl
assID=0 status=0000 clk_okay, last_clk_okay,
device="PPS Clock Discipline", timecode=, poll=2455049, noreply=0,
badformat=0, baddata=0, fudgetime1=0.000, stratum=16, refid=,

(ntpd 4.2.0b at 1.1438-o, used in a Meinberg LANTIME server)

When reading the "peer variables", I get:
assID=0 status=21f4 leap_none, sync_atomic/PPS, 15 events, event_peer/strat_chg,
version="ntpd 4.2.0b at 1.1438-o Tue Oct  7 10:44:09 UTC 2008 (1)",
processor="i586", system="Linux/", leap=00, stratum=1,
precision=-19, rootdelay=0.000, rootdispersion=0.386, peer=54170,
refid=PPS, reftime=cff11bac.e68208bf  Wed, Jul 21 2010  9:09:32.900,
poll=4, clock=cff11bb6.b1f500fe  Wed, Jul 21 2010  9:09:42.695, state=4,
offset=0.000, frequency=75.869, jitter=0.002, noise=0.002,
stability=0.002, tai=0,
access_policy="open access; please notify xxxx at xxxxxxxxxxxx.de for permanent associations",
admin_contact="xxxx at xxxxxxxxxxxx.de",

(some values obfuscated)

Specifically I don't like:
1) "stratum=16", while in the peer it displays: "stratum=1"
2) "timecode=" (without a value, not even double double-quotes (to ease

My suggestions: The PPS should inherit the stratum of the providing
As PPS has no read timecode, we could display "1" when the clock uses
the "assert" edge, or "0" when the pulse uses the "clear" edge.
Otherwise I'd remove the "timecode" variable from the list.

(I was asking Meinberg, whether they use a modified version of ntpd. If
it's not the case, I might file a bug report. But send your opinions


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