6.1 MRS functionality
Page 11
The internal NTP is not requesting the external reference clocks directly. It will see only the internal clock
of the GPS/MRS module with its high precision oscillator OCXO. The controlling of the internal OCXO will be
done by the GPS/MRS module. All osets from the internal reference time to the external reference clocks will
be send to the GPS/MRS clock. The external NTP server will be congured as "server" at the internal NTP
with the option "noselect" only to get the osets to the external NTP servers.
The status information of the activated reference clocks will be shown in the display. The state of the mas-
ter will be marked with "*" or written as text. Also the oset from the reference clock to the internal clock will
be displayed.
1.GPS * 20ns 2.PPS 30ns
2.NTP 30.000us
1.GPS is master : -10ns
2.PPS in is available : -20ns
3.IRIG no signal : n/a
4.NTP is available : -30.000us
2.PTP(IEEE1588)is available : -300ns
F1
MRS Input Priorities
1.GPS * 20ns
2.PPS 30ns
3.NTP 30.000us
M300: LC-Display 40 x 2 Characters
M400 / M900: LC-display, 4 x 16 Characters
M600: Vacuum fluorescent graphic display (VFD), 256 x 64 dots
If an external PTP IEEE1588 grandmaster is available the reference source will be taken prior to the external
NTP server. The PTP time stamping unit will be scanned every 10 seconds (independently of the broadcast
interval of the PTP master). The external NTP server will be scanned every 64 seconds.
After setting the time oset of the internal clock module the NTP will be restarted. Now only small oset
values will be sent to the internal clock module; the ne synchronization mode will start. In the "ne synchro-
nization mode" all osets greater than 10 ms will be ignored 5 times in a row - after the 5 times the oset will be set.
IMPORTANT: After power up the Lantime/MRS the maximum time dierence between internal clock and
external NTP server or PTP grandmaster must be lower than 1000s. Otherwise the internal clock must be set
manually via LC-Display or synchronized by GPS once.
LANTIME M600 MRS
Date: 31st July 2014
11
