G
LOSSARY AND
A
BBREVIATIONS
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]
With reference to the above mentioned error circumstances, the delivered
time offset
of the
NTP should be considered to be at best the most favourable case and in no way to be a value
that takes account of all possible errors.
In order to resolve this problem, NTP delivers the maximum possible error in relation to the
offset. This value is designated as the synchronization distance ("
LAMBDA
") and is the sum
of the
Root Dispersion
and half of the
Root Delay
of all NTP servers used. This value de-
scribes the worst possible case and thus the maximum error that can be expected.
Finally, please note that the user of the Time Server is responsible for the network conditions
between the Time Server and the NTP clients.
As an example, we mention the case where a network has a delay of 500msec and an accu-
racy shift (asynchronous) of 50msec occurs. The synchronised clients will therefore NEVER
achieve accuracy values of one millisecond or even microseconds!
The accuracy value in the GENERAL tab of the WebGUI is designed to help the user to esti-
mate the accuracy.