Specifications

Memory Depth/Record Length
Run/Stop versus Single
The HP 54645A/D both have a Single key and a Run/Stop key. When you
press Run, the trigger processing or update rate is optimized over memory
depth. When you press Single, memory depth is maximized.
Single
For a single acquisition, all available memory is filled with each acquisition,
regardless of sweep speed. To acquire data with the longest possible record
length, use Single.
Running
When running, versus taking a single acquisition, the 1M of memory is
divided in half. This allows the acquisition system to acquire one record while
processing the next acquisition, dramatically improving the number of
waveforms per second processed by the scope. While running, maximizing
the rate at which waveforms are drawn on the display provides the best
picture of your input signal.
At fast sweep speeds, not all of the acquired points fit on the screen.
Numerically, 500,000 points * 1 / 200 MSa/s = 2.5 ms of data, or divided by
10 divisions = 250
µ
s/div. This means that at time base settings of 200
µ
s/div
and faster, the 500,000-point acquisition memory can hold an acquired record
that is wider than the time across the screen.
Run/Stop/Single/Autostore/Erase Operation
Memory Depth/Record Length
4-31