Tektronix CSA7154, User Manual

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Measuring Waveforms
3- 152
CSA7000 Series, TDS7000 Series, & TDS6000 Series Instruments User Manual
H
Noise. (Optional on TDS7000 Series & TDS6000 Series) Tells the instru-
ment if the noise measurement is at the top or the bottom of the eye diagram.
H
Signal Type. (Optional on TDS7000 Series & TDS6000 Series) Lets the
instrument know if the signal to be measured is a pulse waveform or an eye
diagram.
Reference Levels Method.
A second set of levels affect the fidelity of time-related
measurements, the Hi, Mid, and Lo references. For example, the measurement
system takes risetime measurements from the waveform-edge that transitions
from the Low to High reference levels.
You can set the calculation method for each measurement. The instrument
provides the following calculation methods; refer to Figure 3--36 as you read
about each method:
H
Relative Reference Calculated as a percentage of the High/Low range.
H
Absolute Reference Set by absolute values in user units.
Reference level calculation methods
High (50 mV)
High reference
Mid reference (0 mV)
Low reference
Low (--50 mV)
90%
10%
--40 mV
40 mV
50% 0 mV
Figure 3- 36: Reference-level calculation methods