TDS 684A, TDS 744A, & TDS 784A User Manual Glossary–1
Glossary
AC coupling
A type of signal transmission that blocks the DC component of a signal but
uses the dynamic (AC) component. Useful for observing an AC signal that is
normally riding on a DC signal.
Accuracy
The closeness of the indicated value to the true value.
Acquisition
The process of sampling signals from input channels, digitizing the samples
into data points, and assembling the data points into a waveform record. The
waveform record is stored in memory. The trigger marks time zero in that
process.
Acquisition interval
The time duration of the waveform record divided by the record length. The
oscilloscope displays one data point for every acquisition interval.
Active cursor
The cursor that moves when you turn the general purpose knob. It is
represented in the display by a solid line. The @ readout on the display
shows the absolute value of the active cursor.
Aliasing
A false representation of a signal due to insufficient sampling of high
frequencies or fast transitions. A condition that occurs when a oscilloscope
digitizes at an effective sampling rate that is too slow to reproduce the input
signal. The waveform displayed on the oscilloscope may have a lower
frequency than the actual input signal.
Amplitude
The High waveform value less the Low waveform value.
AND
A logic (Boolean) function in which the output is true when and only when
all the inputs are true. On the oscilloscope, that is a trigger logic pattern and
state function.
Area
Measurement of the waveform area taken over the entire waveform or the
gated region. Expressed in volt-seconds. Area above ground is positive; area
below ground is negative.