MITS Janus Time Engine
Page 18 of 39
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3.4.3
Network Time Reference
The Network Time reference is
comprised of two frames: the PTP
Reference Clock and the NTP
Server. Network Time is a choice
for a time reference. The selection
of NTP or PTP are mutually
exclusive. This means that the
system is set up for one or the
other, not both. In changing the setting from one to the other, the MJTE must do a reboot which
will take time to complete. Once complete the desired reference will be available for the
PTP/NTP dropdown selection and only the one that the MJTE has been set up for before reboot.
3.4.3.1
PTP Reference Clock
The PTP as a slave only requires that PTP be set as the network time source. If a PTP master
clock is found and communications are established, the UDP address of the PTP clock will be
shown in the
ADDRESS
box. PTP will be shown as
Active
in the
PTP Reference Clock
frame. This frame will be shone as
Not Active
if NTP is selected. IEEE 802.3/Ethernet
messaging is not supported, therefore MAC addresses will not be collected or shown.
3.4.3.2
NTP Server
When NTP is selected (a radio button connected to the PTP radio button) the IP address of the
desired NTP server must be entered in the
ADRESS
text box of the NTP Server frame. A
missing or invalid address will disable the ability of the MJTE to create an NTP client-server
communications socket. The address is not actually set in the MJTE system until the
Change
button is clicked. When clicked, the value is changed, and this value is saved to flash becoming
the new default for this setting.
The OFFSET is a value in microseconds that is a fixed correction to the NTP time. While NTP
attempts to determine the path length from the server to the client (MJTE) it may be necessary to
add (+ or - value) a correction to this time to result in a more accurate synchronization. This
value is not added to the time calculation until the
Change
button is clicked. When clicked this
offset value is saved to MJTE flash and becomes a new default value.
3.4.4
IRIG Reference
It is important to specify which form of IRIG reference is to be used. The choices are mutually
exclusive in that only one form of IRIG may be used as a reference. The selection of AM or
DCLS is determined by the status of a radio button pair. Choosing AM is choosing that an IRIG
B12x time code source is being used. Any DCLS IRIG B time code source physically connected
will be ignored. The specifications of the IRIG B12X are defined in 1.1.2 IRIG B Inputs on
page 7.
