Tektronix CSA8000B - Manual (Page 334)

Glossary
Glossary- 2 CSA8000B & TDS8000B User Manual
Autoset
A function of the instrument that attempts to automatically produce a stable
waveform of usable size. Autoset sets up the acquisition controls based on the
characteristics of the selected waveform. A successful autoset will produce a
coherent and stable waveform display.
Average acquisition mode
In this mode, the instrument displays and updates a waveform that is the
averaged result of several waveform acquisitions. Averaging reduces the
apparent noise. The instrument acquires data as in sample mode and then
averages it a user-specified number of averages.
Average Optical Power (AOP)
The time averaged measurement of the optical power over a much longer
time period than the bit rate of the signal.
Bandwidth
The highest frequency signal the instrument can acquire with no more than
3 dB (
× .707) attenuation of the original (reference) signal.
BER
An acronym for Bit Error Ratio (or Rate). The principal measure of quality
of a digital transmission system. BER is defined as:
BER = Number of Errors/Total Number of Bits
BER is usually expressed as a negative exponent. For example, a BER of
10
--7
means that 1 bit out of 10
7
bits is in error.
BER floor
A limiting of the bit-error-ratio in a digital system as a function of received
power due to the presence of signal degradation mechanisms or noise.
Bit error
An incorrect bit. Also known as a coding violation.
Channel
An input that connects a signal or attaches a network or transmission line to
sampling modules for acquisition of channel waveforms by the instrument.
Channel/Probe deskew
A relative time delay that is settable for a channel. Setting deskew lets you
align signals to compensate for signals that may come in from cables of
differing length.
Channel icon
The indicator on the left side of the display that points to the position around
which the waveform contracts or expands when vertical scale is changed.
This position is ground when offset is set to 0 V; otherwise, it is ground plus
offset.