HTTP/HTTPS
W
EB
GUI
–
W
EB
B
ROWSER
C
ONFIGURATION
I
NTERFACE
8029HEPTA-V2/GPS GPS - NTP Time Server with LAN Interface - V08.00
69 / 130
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]
8.3.3.4.3 Crystal Operation
Crystal Operation / Switch to Specific Stratum
If the Sync Source (here Module 8024
GPS) runs in crystal operation (status “crystal“) the NTP
service of the Time Server 8029HEPTA/GPS usually behaves in the way that the receipt of
time information is stopped from the Sync Source and the stratum value reset to 16 (defined
as invalid in NTP).
NTP Clients do not accept time information from a NTP Time Server with
stratum 16 (invalid). Briefly, as long as the Time Server 8029HEPTA/GPS
indicates the stratum value 16, NTP Clients are not synchronized.
This behaviour of NTP during crystal operation of the Sync Source can be changed. Therefore
the function "
Switch to specific stratum
" should be enabled by setting the value to "
enabled
"
and the so-called downgrading stratum (= stratum value of the Time Server 8029HEPTA/GPS
during crystal operation of the Sync Source).
For the synchronization of NTP Clients during crystal operation of the Sync Source or for
testing the system without connected synchronization source, in the setting "
enabled
" any
stratum value between 1 and 15 can be set.
Crystal Operation / Stratum in Crystal Operation
The value defined here (range 1-15) designates the transmitted fall back NTP stratum level of
the module in "
Quartz
" synchronization status. Stratum 1 should be configured if downgrading
is not desired in status "Quartz".
The NTP service MUST also be restarted (see
Chapter 8.3.3.6 Restart
Using the option "
Switch to specific stratum
" the NTP Clients are
synchronized with time information indicated in the general menu of the
WebGUI of the Sync Source (here Module 80121GPS) during crystal
operating. Whether this time information (e.g. through drift) is imprecise or
the time is manually set (wrong) cannot be detected by the NTP Client!
In case the value 1 is used for
"Stratum in crystal operation"
, the NTP
Client cannot not verify whether the Time Server 8029HEPTA/GPS is
synchronised or runs in crystal operation. Should a differentiation be
wished between synchronized and crystal operation the downgrading
stratum needs to be set to a value between 2 and 15.
The value is only adjustable if the "
Switch to specific stratum
" function is enabled.
