Gorgy Timing LEDI, User Manual

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MDE-LEDI-1099V4.0 51
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A. NTP Synchronization options
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Polling Rate: By default, NTP polling rate is automatically set to ensure a good synchronization
with the minimum needed packet to reduce network traffic.
But you can force it to 1 request per minute if you want better precision or in another hand reduce
it up to 1 request per 16 minutes to reduce network traffic.
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Use burst: By default, the product will use burst, so instead of sending one NTP packet at a time,
it will sent 8 at each request ensuring less error as extreme value can be easily detected and
discarded with more data. Stay this option enabled unless you have serious restriction on network
trafic.
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Respect server list order: By default, NTP client will try to choose in the list order its
synchronization source. NTP client still send packet to all available server of the list to ensure
security and to check time integrity. If this option is disabled, NTP client will choose its
synchronization server automatically on the "best" time server refering to its stratum, offset ,jitter
and delay. In case of two or more indentical time server in the list, this option may lead to frequent
switch between one or other of the server as they all may be the "best" at least for a moment.
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Force synchronization on first enabled server in case they differ: NTP client have numerous
security to protect product against time inconsitency and/or time hacking.
For exemple, if a system have a large (more than 128ms) offset refering to other server in the list,
it will be discarded (we say it named "false ticker" and a 'x' will appear before server ip in
Synchronization Information). In a two server case, if the two server have large offset between
them, the NTP client cannot know who is the false ticker (the one with wrong time information) and
will prefer to loose synchro-nization (autonomous mode) than synchronize and so possibly take a
wrong time information.
With this option, you could disable this security by telling the NTP client the first sever in the list is
a "sure server". In that case, if some servers have wrong time and the NTP client cannot choose
the right time value by its own, it will synchronize to the "sure server" instead of stay in autonomous
mode.
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Disable timegap security: By default, NTP client cannot change sharply system time (except at
the first synchronization) as it could lead to unstable system time and so unstable system.
So after the first synchronization, it will regularly keep system time updated by steps (control loop).
If you are sure, your servers are stable and have little jitter you could use this option to make
GORGY Product system time update quicker
N.B: to fill in the IP addresses of the NTP servers manually, you have to disable this option, which will
make the fields appear on the web page.