[ntp:questions] Assistance with PPS on Windows

Ken Link klink at numberzero.org
Tue May 3 14:16:47 UTC 2011


We have two 32 bit Windows XP SP3 machines here for testing an Arbiter
1093C GPS clock and a Meinberg TCR511PCI IRIG card. Both systems are
running NTP 4.2.6p3 stable. System A is synced via serial port to the
Arbiter clock and is a stable Stratum 1 server. System B has the
Meinberg IRIG card and is currently having issues. The unmodulated
IRIG-B output of the Arbiter is connected to the card’s serial port
and we are using the MbgMon utility to verify the IRIG configuration
is correct and the signal is being read (the time adjustment service
from within MbgMon is disabled). Our goal is to have the PPS output of
the card “loop back” via serial cable into the COM1 port on the
motherboard,  then configure NTP with two sources, one being PPS from
COM1 and the other being a network peer of System A (with the prefer
keyword, for the PPS driver).

The problem is we cannot get NTP to sync to the PPS output. The PPS
source shows up in “ntpq –p” however it has 0 reach. System B is
synced to System A and is a stable Stratum 2 server at the moment.
MbgMon on System B shows the PPS output on the card is active. The
IRIG signal is 100% and shows it is synced. I’ve installed the
serialpps driver, rebooted and verified it was loaded in the Device
Manager, set the PPSAPI_DLLS global environment variable
appropriately, etc.

Any suggestions on how to troubleshoot this?


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