HP 54710A User's Reference Manual page 309

Utility Menu
System Configuration
Time and Date
The oscilloscope has a 24-hour clock that it uses to stamp a time and date on
waveforms when they are acquired. It also places a date and time stamp on
files stored to the disk drive, on waveforms transferred over the HP-IB bus,
and on waveforms that are printed. A printed waveform has both the time it
was acquired and the time it was printed listed on the printout.
The oscilloscope uses the same clock when it lists the date and time of the
last calibration in the Cal status and Utility screens.
To change the time or date, simply press the Time softkey or the Date
softkey. Then, change the time or date with the knob, arrow keys, or keypad.
Declassify frame memory
Declassifying the memory in the mainframe is a method to ensure sensitive
information is not seen by individuals without the proper clearance.
Declassifying the mainframe places zeros in the oscilloscope's RAM memory.
This clears all the setup memories, waveform memories, pixel memories,
front-panel setups, channel memories, and function memories. Declassify the
mainframe in situations when you are concerned about the security of the
work you are performing.
For example, you would declassify the mainframe when you are going to
leave the oscilloscope unattended for awhile or when someone is visiting your
area that does not have the clearance to know about your work. When the
oscilloscope is not declassified, there is always the possibility that someone
could analyze the front-panel setups or RAM memory of the oscilloscope to
determine the type of work you are performing. After the oscilloscope
declassifies the memory in the mainframe, the screen displays the message
"Frame Memory is Declassified." This message stays on the screen until the
oscilloscope is no longer declassified.
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