Tektronix CSA7154, User Manual

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Glossary
CSA7000 Series, TDS7000 Series, & TDS6000 Series Instruments User Manual
Glossary- 15
Setup/Hold trigger
A mode in which the instrument 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.
Selected waveform
The waveform on which all measurements are performed, and which is
affected by vertical position and scale adjustments. The light over one of the
channel selector buttons indicates the current selected waveform.
Single-Mode Cable
An optical cable with a very small core diameter (usually in the range of
2-10 microns). Such cables are normally used only with laser sources due to
their very small acceptance cone. Since the cone diameter approaches the
wavelength of the source, only a single mode is propagated.
Slew Rate trigger
A mode in which the instrument triggers based on how fast a pulse edge
traverses (slews) between an upper and lower threshold. The edge of the
pulse may be positive, negative, or either. The instrument can trigger on slew
rates faster or slower than a user-specified rate.
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
instrument is used to gather security
sensitive data, such as is done for research or development projects.