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8030HEPTA/GPS GPS - NTP Time Server with 2x 10/100/1000 MBit LAN Interface - V04.00
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hopf
Elektronik GmbH
Nottebohmstr. 41
• D-58511 Lüdenscheid • Tel.: +49 (0)2351 9386-86 • Fax: +49 (0)2351 9386-93 • Internet: http://www.hopf.com • E-Mail: [email protected]
Following configuration steps for the activation of the NTP time ba-
sis are required:
•
Select the desired NTP time base.
•
Transfer the setting with
Apply Changes
to the Time Server.
•
Fail-save storage of the configuration by pressing
Save to Flash
within 10 seconds
.
Depending on the activated time base leap a board reset might be
released after transfer with Apply Changes eliminating non saved
configurations.
UTC - NTP with Time Basis UTC
According to the RFC standard NTP uses only the UTC time base.
NTP with the Time Base Standard Time
Using the NTP time protocol with the standard time base the released time information corre-
spond with UTC plus the time difference, adjusted in the base system
without
considering the
daylight saving time changeover.
NTP with the Time Base Local Time
Output of the NTP time protocol with the local time base the released time information corre-
spond with UTC plus the time difference and the additional offset for the possible summer
time, adjusted in the base system.
NTP does not allow any leaps in time. Using the NTP time protocol with the local time base
the internal NTP process of a board is restarted based on a summer-/winter time adjustment.
Using the NTP time protocol with the local time base the summer-/winter
time adjustment is released one to two minutes belated.
Afterwards the local time is correctly available in the NTP time protocol.
Therefore, within this transition period a requested NTP time protocol is re-
plied by the former time base.
Changing the time base for the output of the protocol for NTP is only de-
signed for customized applications and does not correspond with the stand-
ard of NTP. The synchronisation of a standard NTP-Client with a time basis
deviating from UTC results in a wrong time information in the standard NTP-
Client and might cause time leaps!