Tektronix CSA8000B Series, User Manual

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Appendix B: Automatic Measurements Reference
B- 46
CSA8000B & TDS8000B User Manual
Table B- 7: NRZ Measurements - Amplitude (cont.)
Name Definition
NRZ Optical Modulation
Amplitude An approximation defined as the difference of the logical power 1 and 0 determined in a vertical
slice through the eye crossing. The levels are determined as the means of the histograms of the
vertical data slice through the High (logical 1) and Low (logical 0) levels.
NRZ OMA [watts]
=
P 1
−
P 0
Where:
H
P1 and P0 are the average power levels of the logical 1 and 0, determined at the eye
crossing.
This measurement requires the use of a waveform database. When this measurement is turned
on, it will automatically set the measurement system to use a waveform database. If a
waveform database is not available, no valid measurement results will be produced. See
Use a
Waveform Database on page B--70.
NRZ Peak-to-Peak The difference between the Max and Min vertical values of the selected waveform within the
measurement region. See
Defining and displaying waveforms on page 3--56.
NRZ Peak-to-Peak = Max – Min
Where Max and Min are the maximum and minimum measurements.
If enabled, measurement gates constrain the measurement region to the area between the Start
Gate (G1) and Stop Gate (G2). See
To Localize a Measurement on page 3--83.
When this measurement is turned on, it will automatically set the measurement system to use a
waveform database if available. See
Use a Waveform Database on page B--70.
For best results with this measurement:
H
Perform a Dark Level compensation before taking this measurement if the source of the
measured waveform is an optical channel. See
To Perform Dark-Level and User
Wavelength Gain Compensations on page 3--98.
H
Optimize the vertical resolution before taking this measurement. See How to Optimize the
Vertical Resolution on page B--70.