[time-nuts] Symmetricom TymServe 2100-GPS currently fails with GPS offset

Esa Heikkinen tn1ajb at nic.fi
Fri Jan 23 16:36:30 EST 2015


It seems that there's serious bug in Symmetricom Tymserve 2100 most 
recent firmware (V4.1). When leap second pending flag was added to GPS 
transmission (according to data shown by Lady Heather) the Tymserve's 
time started to be exactly 1 second late from UTC!

Currently it claims that current UTC offset is 17 seconds, while Lady 
Heather shows 16 seconds. Also if I compare the NTP time with another 
NTP servers it is really 1 seconds late.

Playing with telnet:

? utcoffset
GPS --> UTC Offset = 17

(And of course there's no way to set this manually)

However in the utcinfo data the dTLs value received from GPS is correct 
(16) but it seems that Tymserver firmware uses wrong value dTLsf, which 
is the future value of UTC offset after leap second event:

? utcinfo
A0:0.0000000 A1:0.0000000 dTLs:16 ToT:61440.0000000 WNt:1829 WNLsf:1851 
DN:3 dTLsf:17

It seems that there's no way to fix this. There's also leap second 
command available, having no efffect on this. Everyone who owns this 
device please check what's going on with it...

To me this is somehow suprising, assumed this to be professional grade, 
reliable and trouble free instrument, but obviously it's not. No wonder 
why these are sold so cheap on Ebay (where I got mine).

Maybe only way is to run this with 1PPS from Thunderbolt until the leap 
second period is over.


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