Glossary
TDS 684A, TDS 744A, & TDS 784A User Manual Glossary–3
Cycle area
A measurement of waveform area taken over one cycle. Expressed in
volt-seconds. Area above ground is positive; area below ground is negative.
Cycle mean
An amplitude (voltage) measurement of the arithmetic mean over one cycle.
Cycle RMS
The true Root Mean Square voltage over one cycle.
DC coupling
A mode that passes both AC and DC signal components to the circuit.
Available for both the trigger system and the vertical system.
Delay measurement
A measurement of the time between the middle reference crossings of two
different waveforms.
Delay time
The time between the trigger event and the acquisition of data.
Digitizing
The process of converting a continuous analog signal such as a waveform to a
set of discrete numbers representing the amplitude of the signal at specific
points in time. Digitizing is composed of two steps: sampling and quantizing.
Display system
The part of the oscilloscope that shows waveforms, measurements, menu
items, status, and other parameters.
Edge Trigger
Triggering occurs when the oscilloscope detects the source passing through a
specified voltage level in a specified direction (the trigger slope).
Envelope acquisition mode
A mode in which the oscilloscope acquires and displays a waveform that
shows the variation extremes of several acquisitions.
Equivalent-time sampling (ET)
TDS 700A Models Only: A sampling mode in which the oscilloscope
acquires signals over many repetitions of the event. The TDS 744A and
TDS 784A Oscilloscopes use a type of equivalent time sampling called
random equivalent time sampling. It utilizes an internal clock that runs
asynchronously with respect to the input signal and the signal trigger. The
oscilloscope takes samples continuously, independent of the trigger position,
and displays them based on the time difference between the sample and the
trigger. Although the samples are taken sequentially in time, they are random
with respect to the trigger.