Model: MC-1-M (2U)
Doc. Ref. no. : m05/om/101
Issue no. 14
User’s Manual
Page 76 of 103
Master Clock MC-1-M model operates at stratum level 1 which is considered next accurate time source to
GPS Satellites. Other NTP clients stratum level increases by 1 as NTP devices goes downwards in
network layers. Stratum level can be upto maximum 14 to be considered as valid NTP time source.
NTP client accuracy also depends on the hierarchical arrangement of NTP servers and NTP clients in
network because the stratum value increases by 1 at every hierarchical stage in network and as stratum
value increases, the accuracy of NTP client decreases depending on the type of NTP server’s clock
accuracy in hierarchy, processing capabilities of multiple NTP requests and transmission delays.
•
If the stratum level of GPS Master Clock Model MC-1-M device is
configured at 15 under Unlock conditions, no NTP client will synchronize its
time with NTP server output as level 15 is the last limit of stratum as per
NTP standard.
•
Stratum of GPS Master Clock MC-1-M under Unlock conditions should be
such that last NTP client in hierarchical arrangement should be at stratum
level 15 so that can be continuously synchronized with its superior level
NTP source device.
•
I.P. address of two NTP ports in GPS should not be same if both NTP ports
are to be used in same network domain.
•
It is recommended that NTP output in network should be used only when
once GPS Master Clock Model MC-1-M is Lock after being power UP. If
GPS Master Clock Model MC-1-M device was in Power OFF condition for
very long duration, RTC battery may get discharged and RTC time will
reset to its default time. (Please check the applicable battery backup period
mentioned in RTC section).
NOTE:
•
Factory set IP of NTP ports are 192.168.100.153(NTP1)&192.168.100.154(if NTP2 is available
as optional output).
•
I.P. address of two NTP ports in GPS should not be same if both NTP ports are to be used in
same network domain.
•
Among all applicable NTP parameters in NTP packet format, only stratum value can be modified
for GPS Master Clock Model MC-1-M Unlock condition only. If GPS Master Clock Model MC-1-M
NTP output stratum value is configured as 15, all NTP clients in network will continue to ignore
GPS Master Clock Model MC-1-M NTP output as valid time source.
•
As NTP protocol is based on UDP transmission protocol (as UDP is a connectionless protocol as
there is no acknowledgment for failed packet delivery), NTP requests from NTP clients to NTP
servers and NTP responses from NTP servers to NTP clients can be delayed at irregular intervals
or rarely discarded if there too much Ethernet packets load/congestion in network.
•
There may be rare case that NTP Server responses to some NTP requests from NTP clients may
be discarded, if there is large number of simultaneous NTP requests to single NTP server port.
•
It is recommended that NTP output in network should be used only when once GPS Master Clock
Model MC-1-M is Lock after being power UP. If GPS Master Clock Model MC-1-M device was in
Power OFF condition for very long duration, RTC battery may get discharged and RTC time will
