Tektronix 2221A - Glossary; Rise time; Roll; RS-232-C interface

Glossary
Rise time
The time it takes for a ieading edge of a pulse to rise from 10% to 90% of
its amplitude.
Roll
A slow-speed storage mode where the acquired data first appears at the
right side of the display and forms a record that continues to scroll right
to left across the display at a rate set by the time base.
RS-232-C interface
A communications device that conforms to the Electronic Industries
Association (EIA) RS-232-C standard for data terminal or data commu
nications equipment.
Sampling
The internal process of the oscilloscope that captures an analog input
(such as a voltage) at a discrete point in time and holds it constant until
it is quantized. Two general methods of sampling are:
real-time sampling
and equivalent-time sampling.
Sampling Rate
This is the actual frequency at which the oscilloscope takes a sample.
This frequency may be expressed in samples/second or hertz.
Scan
A siow-speed storage mode that updates the acquisition display left to
right across the display at a rate determined by the time base setting.
Selected waveform
The waveform on which cursor measurements are performed. The
symbol underscores the selected memory location indicated by 1,2, 3,
or 4K. The symbol appears under the letter “A” when the waveform
selected is the current acquisition.
Setup (menus)
A group of related controls for major oscilloscope functions that are
located on the front panel of the oscilloscope above the intensity control.
Slope
The rising or falling edge of a signal (signal transition) that is selected for
triggering the horizontal sweep of the oscilloscope.
Smooth
A digital process that examines the change in value of data points
between adjacent intervals and reorders them for correct slope (and a
smoother waveform) if the change in value does not exceed a certain
limits.
Sweep
Time-dependent information created by the electron beam moving
across a CRT screen.
Time base
The set of parameters that let you define the time and horizontal axis
attributes of a waveform.
2221A User Manual
G-5