Specifications

To operate the time base controls
The following exercise guides you through the time base keys, knobs, and
status line.
•
Turn the Time/Div knob and notice the change it makes to the status
line.
The Time/Div knob changes the sweep speed from 2 ns to 50 s (HP 54645A)
and from 5 ns to 50 s (HP 54645D) in a 1-2-5 step sequence, and the value is
displayed in the status line.
•
You can access the horizontal Vernier softkey by pressing the
Main/Delayed
key.
The Vernier softkey allows you to change the sweep speed in smaller
increments with the Time/Div knob. These smaller increments are
calibrated, which result in accurate measurements, even with the
vernier turned on.
•
You can check the sample rate by pressing the
Main/Delayed
key
when the instrument is running, during a single run, or when the
instrument is stopped. The sample rate is also displayed when the
acquisition stops or ends.
•
Turn the Delay knob and notice that its value is displayed in the status line.
The Delay knob moves the main sweep horizontally, and it pauses at
0.00 s, mimicking a mechanical detent. At the top and bottom of the
graticule is a solid triangle (
▼
) symbol and an open triangle (
∇
)
symbol. The
▼
symbol indicates the trigger point and it moves with
the Delay knob. The
∇
symbol indicates the time reference point. If
the time reference softkey is set to left, the
∇
is located one graticule
in from the left side of the display. If the time reference softkey is set
to center, the
∇
is located at the center of the display. The delay
number tells you how far the reference point
∇
is located from the
trigger point
▼
.
Front-Panel Overview
To operate the time base controls
2-27