MITS Janus Time Engine
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2.1
NTP Decode/Correction
The NTP synchronizer requires a valid and reachable TCP/IP address to establish a client (JTE
Master Controller)/server (NTP clock) relationship. Once a client session is begun with the NTP
server, the JTE Master Controller will use its time and compensate for measurable loop delays.
The JTE Master Controller adjusts the NCO frequency driving the time master such that there is
a fixed number of counts between one second intervals such that the seconds rollover is aligned
with the NTP server. This method avoids jam sync jumps in the fractional seconds.
When synchronization is successfully achieved and Network Time -NTP is selected, the JTE
Master Controller will indicate a locked condition in the webserver and report such status via a
command.
2.2
PTP Synchronizer Algorithm
The PTP is an IEEE standard 1588 V2 synchronizer that requires a PTP boundary or Grand
Master clock be operating on the visible network. Once a UDP multicast session is established
between the PTP master and the JTE Master Controller, the time message exchanges initiated by
the PTP master clock will begin.
The details of the exchange are fully compliant with IEEE 1588 V2 for UDP packets. Fully
compensated PTP time will be used to adjust the NCO frequency driving the time master such
that there is a fixed number of counts between one second intervals and the zero rollover aligns
with the PTP 1-second rollover. This method avoids jam sync jumps in the fractional seconds.
When synchronization is successfully achieved and Network Time – PTP is selected, the JTE
Master Controller will indicate a locked condition in the webserver and report such via a
command.
3.0
WEBSERVER
When the Ethernet connection is set to DHCP (factory default), the address assigned to Janus by
the network router or server will have to be known to the user. If set to a fixed IP address, that
address must be used.
The webserver provides status of MJTE. Status includes the time, lock status and time reference
in use (IRIG, 1PPS, Network Time or optional GPS).
The webserver is best used with MS Edge or Firefox.
It may be set to require login or not. If login is set, the correct username and password must be
entered in order to gain access, for details see paragraph 3.3 Change Login page 16.
It is important to know that the cursor activates the page frame. When the cursor is moved to
another frame, all remaining frames are disabled for input. In making changes to any settings,
keep the cursor in the relevant frame until the change is reported back to the page. In addition,
when a mouse pointer is within one of the frames, display update from the MITS system will be
suspended to avoid conflicts between the desired user input and status reported by the system. If
the mouse is not moved for 15-20 seconds, updates will resume.
The general organization of the webserver is shown below.
