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 124
C H A P T E R T E N
125 M e r i d i a n I I U s e r M a n u a l
R E A R - P A N E L I / O
Use the CONFIG->STORE menu to save the settings to non-volatile memory.
2. Verify that the 5071A is not in STANDBY mode. If it is, you must change it to NORMAL using
the CONFIG->MODE menu.
3. Connect the provided DB9F-to-DB9F null-modem cable between the 5071A Cesium Control Mod-
ule connector labeled “Cesium Control I/O” and the 5071A DB9M connector labeled “RS-232C”.
4. Connect the provided BNC-to-Type-N coaxial cable between the Control Module connector la-
beled “10 MHz Sine Input” and the 5071A connector labeled “Port 1”.
5. Apply power to the Meridian II.
Operation
After the Meridian II has booted, verify that the 5071A Cesium Control Module was detected in the
I/O->OptCard1 menu item display. Then move to the Receiver->Osc_Stat menu and scroll through
the items which appear there. The oscillator type displayed should be either Cesium or US-Cesium
(if the 5071A has the Option 001 High-Performance beam tube). If you continue scrolling through
these items, you will eventually get to a group of twelve 5071A-specific parameters:
Operation Status register (in human-readable format),
Questionable Data register (in human-readable format),
Cesium Beam current,
C-Field current,
Ion Pump current,
Electron-multiplier voltage,
Cesium Beam tube oven voltage,
Signal Gain percent of maximum,
1
st
microwave RF amplitude percent of maximum,
2
nd
microwave RF amplitude percent of maximum,
Reference oscillator oven voltage,
Reference oscillator control percent of maximum.
Alternatively, you may use the
hp5071astat
command to get this information. See on the next sec-
tion called Cesium Status Using the Console Port .
At this point, the Meridian II will continuously monitor the operating status of the 5071A and will
remain in the Warm-Up state until the 5071A has warmed up and is indicating NORMAL operation
in the Operation status register. At this time, the Meridian II will transition to the Acquire state and
remain there until satellites are tracked, at which point it will begin the normal GPS synchronization
and frequency locking process. Once Locked status has been achieved, the Meridian II will set the
time-of-day clock on the 5071A front panel to GPS time, and turn on the display. Prior to this, the
5071A clock display will be blank. The GPS time on the 5071A display is only accurate to about 1⁄2
second. (For more accurate display of time-of-day, and to display UTC or Local time, use the front
panel display of the Meridian II.)
After achieving lock at its relatively short initial control loop averaging time, the Meridian II will
steadily lengthen the control loop averaging time for several weeks before it has reached its final