EndRun Meridian II, Руководство пользователя

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M e r i d i a n I I U s e r M a n u a l 54
C H A P T E R F O U R
55 M e r i d i a n I I U s e r M a n u a l
H T T P S I N T E R F A C E
Receiver: Oscillator Page
This page shows system oscillator control information for the GPS Subsystem:
Oscillator Status
Oscillator Type This field shows the system oscillator type that is installed in Meridian II. It
will be either TCXO (standard), or the optional MS-OCXO, HS-OCXO,
US-OCXO, Rubidium or US-Rubidium.
DAC
The system oscillator control DAC value indicates the frequency control setting.
The system automatically sets this value to remove frequency errors. Values
may range from 0 to 1,048,575. Values close to the minimum or maximum will
set the DAC fault flag.
Measured This field shows the last measured time offset of the GPS Subsystem relative to
Time Error GPS while locked, in second.
Time Deviation This field shows the time deviation (TDEV) of the offset measurements in
seconds. The tau associated with this measurement is one second, which is the
update interval of the position fixes received from the GPS Receiver.
Oscillator This field shows the regression-computed system oscillator ageing rate per day
Ageing Rate (several-hours delay before the first measurements are displayed).
Control Loop TAU This field shows the system oscillator control loop averaging time constant, in
seconds. It’s value is automatically adjusted to maintain optimum offset and
stability.
Coast Duration This shows the number of seconds the GPS Subsystem has been in coast mode,
while Meridian II is unlocked to GPS. Coast mode is another term for holdover
mode.
Estimated Time This is the estimated time error of the GPS Subsystem when in coast/holdover
Error mode, in seconds.
Internal Chassis Internal chassis temperature in °C. Available with OCXO or Rubidium
Temperature oscillators.
Clock Page
This page shows the configuration of the Meridian II Precision TimeBase except for any optional I/O
which is listed on the I/O page.
Clock Configuration
Time Mode This field shows the current time mode setting. Possible settings are UTC, GPS
and Local. Since NTP always uses UTC, this setting only affects the front-
panel display and any optional Time Code or Serial Time outputs. For example,
if this field shows Local, then the time shown on the front-panel display will be
Local time but NTP will remain at UTC time. To change the time mode setting
use the
systimemodeconfig
command via the console port.