HP 54520 Series - Time;Div Softkey

See Also
Horizontal
Time/Div Softkey
Time/Div Softkey
The top softkey in the horizontal menu is the time /div softkey, which
displays the horizontal scaling factor. When the scope is running, this softkey
also displays the current sample rate. You can use the horizontal knob to
change the time base scaling at any time, even if you are in a different menu
or when the time/div softkey is not the active function. However, when the
time/div softkey is the active function, you can use either the horizontal knob,
keypad, or the entry knob to change the horizontal scaling.
Horizontal scaling changes in a 1-2-5 sequence from 500 ps/div to 5 s/div.
When the HP 54540 is samping at 1 GSa/s in the real-time mode, the 500 ps
setting is not available. When the HP 54540 and HP 54520 are sampling at
500 MSa/s in the real-time mode, the 500 ps and 1 ns setting are not available.
The fine key does not affect the time base sequence while the acquisition is
running, unless the auto adjust softkey is set to adjust.
The horizontal scale setting affects the sample rate at which the oscilloscope
acquires data, except when the sample clock softkey is set to adjust in the
real-time mode. When the scope is running, the current sample rate is
displayed below the time/div setting in the time base menu.
In the real-time mode and with the acquisition stopped, the time/div knob
also controls the zoom feature. By observing the memory bar, you can tell
what portion of the memory is being displayed.
An acquisition is not displayed on the screen until all data is available. The
data is available when the waveform record is full. The advisory "running" is
displayed after the scope triggers.
When the sample clock and record length are set such that it takes two
seconds or longer to collect the data, the advisory "” sec (prestore)" is
displayed while pretrigger data is collected, and "x sec (poststore)" is
displayed while posttrigger data is collected. These messages indicate the
time needed to complete an acquisition, where 7 is the remaining time in
seconds, and continues to count down until the time has elapsed.
The total time acquired and the sample rate are dependent on the sample
clock setting and the selected record length of the acquisition (as per table
4-1).
"Repetitive/Real-Time Softkey" in this chapter for information on sampling
modes.
4-4