Appendix B: Automatic Measurements Reference

CSA8000B & TDS8000B User Manual B-45

Table B- 7: NRZ Measurements - Amplitude (cont.)
Name Definition
NRZ +Overshoot The ratio of the maximum value of the measured signal to its amplitude, expressed as a
percentage. The waveform is scanned for the maximum value within the measurement region,
while the amplitude is measured in the Eye Aperture.
Where Max is the signal maximum, and High and Low are the logical 1 and 0 levels. See
NRZ Eye-Aperture Parameters on page B--65.
The Eye Aperture is adjustable and defaults to 20% of the NRZ bit time. See RZ Eye Aperture
Parameters on B--62.
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:
HPerform 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.
HOptimize the vertical resolution before taking this measurement. See How to Optimize the
Vertical Resolution on page B--70.
NRZ +Overshoot =100 ×(Max −High)
(High −Low)
NRZ - Overshoot The ratio of the minimum value of the measured signal to its amplitude, expressed as a
percentage. The waveform is scanned for the minimum value within the measurement region,
while the amplitude is measured in the Eye Aperture.
Where Min is the signal minimum, and High and Low are the logical 1 and 0 levels.
The Eye Aperture is adjustable and defaults to 20% of the NRZ bit time.
If enabled, measurement gates constrain the measurement region to the area between the Start
Gate (G1) and Stop Gate (G2).
When this measurement is turned on, it will automatically set the measurement system to use a
waveform database if available.
For best results with this measurement:
HPerform 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.
HOptimize the vertical resolution before taking this measurement. See To Optimize the
Vertical Resolution on page B--69.
NRZ −Overshoot =100 ×(Low −Min)
(High −Low)