Tektronix CSA8000B - Manual (Page 336)

Glossary
Glossary- 4 CSA8000B & TDS8000B User Manual
Error detection
Checking for errors in data transmission. A calculation is made on the data
being sent and the results are sent along with it. The receiving station then
performs the same calculation and compares its results with those sent. Each
data signal conforms to specific rules of construction so that departures from
this construction in the received signals can be detected. Any data detected
as being in error is either deleted from the data delivered to the destination,
with or without an indication that such deletion has taken place, or delivered
to the destination together with an indication that it is in error.
Error rate
The ratio of the number of data units in error to the total number of data
units.
Edge trigger
Triggering occurs when the instrument detects the source passing through a
specified voltage level in a specified direction (the trigger slope). This
instrument supports only edge triggering. All trigger sources must be
external, except when using clock recovery (available as an option with
optical sampling modules) or the internal clock.
Envelope acquisition mode
A mode in which the instrument acquires and displays a waveform that
shows the variation extremes of several acquisitions.
Equivalent-time sampling (ET)
A sampling mode in which the instrument acquires signals over many
repetitions of the event. This instrument uses a type of equivalent-time
sampling called sequential equivalent-time sampling. See Sequential
equivalent-time sampling.
Extinction Ratio
The ratio of two optical power levels of a digital signal generated by an
optical source. P
1 is the optical power level generated when the light source
is high, and P 2 is the power level generated when the light source is low.
r
e
= P 1
P
2
Gated measurements
A feature that lets you limit automated measurements to a specified portion
of the waveform. You define the area of interest using measurement gates.
General-purpose knob
The large front-panel knob on the upper-right corner of the front panel. You
can use it to change the value of the control or element that currently has
focus. It can adjust the cursors.
GPIB (General Purpose Interface Bus)
An interconnection bus and protocol that allows you to connect multiple