Tektronix TDS5054, Руководство пользователя

Страница: 337 / 361

Glossary
Glossary- 10
TDS5000 Series User Manual
Sample interval
The time interval between successive samples in a time base. For real-time
digitizers, the sample interval is the reciprocal of the sample rate. For
equivalent-time digitizers, the time interval between successive samples
represents equivalent time, not real time.
Sampling
The process of capturing an analog input, such as a voltage, at a discrete
point in time and holding it constant so that it can be quantized. Two general
methods of sampling are:
real-time sampling
and
equivalent-time sampling.
Screen text
Lines displayed on screen that you use to indicate measurement reference
levels and points that an automatic measurement is using to derive the
measurement value.
Setup/Hold trigger
A mode in which the oscilloscope triggers when a data source changes state
within the setup or hold time relative to a clock source. Positive setup times
precede the clock edge; positive hold times follow the clock edge. The clock
edge may be the rising or falling edge.
Slope
The direction at a point on a waveform. You can calculate the direction by
computing the sign of the ratio of change in the vertical quantity (Y) to the
change in the horizontal quantity. The two values are rising and falling.
Statistical measurement
An automated measurement that is derived from color-graded waveform data
and is based on histograms computed at the crossing levels. A statistical
measurement can be selected only in color-graded display mode.
Tek Secure
This feature erases all waveform and setup memory locations (setup memories
are replaced with the factory setup). Then it checks each location to verify
erasure. This feature finds use where this oscilloscope is used to gather
security sensitive data, such as is done for research or development projects.
Time base
The set of parameters that let you define the time and horizontal axis
attributes of a waveform record. The time base determines when and how
long to acquire record points.
Timeout trigger
A trigger mode in which triggering occurs if the oscilloscope does not find a
pulse of the specified polarity and level within the specified time period.
Trace
The visible representation of an input signal or combination of signals.
Identical to waveform.