I have a small embedded linux machine. Moxa UC-7112 Plus that I want to
use as NTP server. http://www.moxa.com/product/UC-7110-LX.htm
Its has MOXA ART ARM9 32-bit 192 MHz processor CPU.
Here are statistics I collected after using it a bit. This is using gpsd
2.33 to collect NMEA, PPS.
remote refid st t when poll reach delay offset
jitter
==============================================================================
+SHM(0) .NMEA. 0 l 8 16 377 0.000 -21.691
7.812
*SHM(1) .PPS. 0 l 1 16 377 0.000 -17.105
7.81
ntpq> cv
status=0101 clk_noreply, last_clk_noreply,
device="SHM/Shared memory interface", timecode=, poll=54, noreply=78,
badformat=0, baddata=0, fudgetime1=0.000, stratum=0, refid=PPS, flags=0
ntpq> rv
status=09e4 leap_none, sync_telephone, 14 events, event_peer/strat_chg,
version="ntpd 4....@1.786 Tue Sep 11 19:14:27 CDT 2007 (1)",
processor="armv4tl", system="Linux2.6.9-uc0", leap=00, stratum=1,
precision=-7, rootdelay=0.000, rootdispersion=32.592, peer=4253,
refid=PPS, reftime=cd44982f.b9359791 Tue, Feb 17 2009 9:58:07.723,
poll=4, clock=cd449838.649a9973 Tue, Feb 17 2009 9:58:16.392, state=4,
offset=-13.494, frequency=142.853, jitter=7.908, stability=4.197
r...@moxa:~# cat /proc/cpuinfo
Processor : ARM922Tid(wb) rev 1 (v4l)
BogoMIPS : 76.59
Features : swp half thumb
CPU implementer : 0x66
CPU architecture: 4
CPU variant : 0x0
CPU part : 0x526
CPU revision : 1
Cache type : VIVT write-back
Cache clean : cp15 c7 ops
Cache lockdown : format B
Cache format : Harvard
I size : 16384
I assoc : 2
I line length : 16
I sets : 512
D size : 16384
D assoc : 2
D line length : 16
D sets : 512
Some gpsd messages in case :
gpsd: <= GPS: $GPZDA,020012.000,17,02,2009,,*58
gpsd: carrier-detect on /dev/ttyM1 changed to 0
gpsd: carrier-detect on /dev/ttyM1 changed to 1
gpsd: ntpshm_pps: precision -6
ntp.conf
server 127.127.28.0 minpoll 4 maxpoll 4
fudge 127.127.28.0 time1 0.411 refid NMEA
server 127.127.28.1 minpoll 4 maxpoll 4 prefer
fudge 127.127.28.1 refid PPS
I am curious if the platform is the limitation, or if there are things that
can be done to make this work well as a NTP server, because now the accuracy
is unacceptable. Ideas?
_______________________________________________
questions mailing list
questions@lists.ntp.org
https://lists.ntp.org/mailman/listinfo/questions
