Mobatime DTS 4801.masterclock, Instruction Manual

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8.3 Fix stratum for local time source
In operation with NTP time sources and the parameter "Local time source = off", the
behavior of the NTP server is that of a standard NTP server. When the time sources
are no longer available or invalid, the NTP server becomes unsynchronized after a
short time as per NTP algorithm.
To provide multicast NTP for slave clock lines, the NTP server has to remain
synchronized. An unsynchronized server does not send out any time. The slave clocks
in this case will run to the 12 o'clock position.
Therefore, in this case it makes sense to set the
Fix stratum
value
unequal to 0
and if
only NTP time sources are in use for the synchronization of the DTS 480x, to set the
local time source to
local
.
Time source(s) Fix stratum = 0 Fix stratum > 0
DCF/GPS with NTP
DCF ok: Stratum DTS 480x always
1, Time always from DCF
DCF nok: If NTP is available
Stratum DTS 480x =
Stratum NTP 1
Else: Stratum is increased as per
set stratum timeout value
till NTP server is
unsynchronized
(Stratum DTS 480x = 16)
DCF ok: Stratum DTS 480x always 1,
Time always from DCF
DCF nok: If NTP is available
Stratum DTS 480x =
Stratum NTP 1
Else: Stratum is increased as per
set stratum timeout value
till stratum of time source =
Fix stratum
 Stratum DTS 480x now
keeps fix s 1
DCF/GPS without
NTP
DCF ok: Stratum DTS 480x always
1, Time always from DCF
DCF nok: Stratum is increased as per
set stratum timeout value
till NTP server is
unsynchronized
(Stratum DTS 480x = 16)
DCF ok: Stratum DTS 480x always 1,
Time always from DCF
DCF nok: Stratum is increased as per
set stratum timeout value
till stratum of time source =
Fix stratum
 Stratum DTS 480x now
keeps fix s 1
Local with NTP
NTP ok: Stratum DTS 480x =
current NTP 1
NTP nok: Stratum of the local time
source is increased as per
set stratum timeout value
after DTS 480x start 
normally the NTP server is
unsynchronized quite fast
when NTP time source is
failed
Attention:
no reasonable
configuration
NTP ok: Stratum DTS 480x =
current NTP 1
NTP stratum of NTP
time source > Fix stratum
NTP nok: Stratum DTS 480x =
fix s 1
Local without NTP
Only for testing purposes for a DTS
480x without any time source which
should nevertheless have a NTP time
server with a valid time.
The stratum of the DTS 480x starts
from 0 to unsynchronised as per set
stratum timeout value. Only for testing purposes for a DTS
480x without any time source which
should nevertheless have a NTP time
server with a valid time.
The stratum of the DTS 480x is
Fix
stratum
+ 1.