Tektronix CSA8000B Series, Руководство пользователя

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Appendix B: Automatic Measurements Reference
B- 52
CSA8000B & TDS8000B User Manual
Table B- 8: NRZ Measurements - Timing (cont.)
Name Definition
NRZ Fall Time NRZ Fall Time characterizes the negative slope of the NRZ eye by computing the time interval
between the mean crossings of the high reference level and the low reference level.
RZ Fall Time = TcrossL -- TcrossH
Where TcrossL is the mean of the histogram of the crossing of the low reference level, and
TcrossH is the mean of the histogram of the crossing of the high reference level. See
NRZ
Measurement Reference Levels on page B--63.
The adjustable low reference and high reference levels default to 10% and 90% of the NRZ eye
amplitude.
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.
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 available.
See
Use a Waveform Database on page B--70.
NRZ Frequency NRZ Frequency is defined as half of the inverse of the time interval between two consecutive
eye crossing points (i.e. the reciprocal of the Period). It would be the frequency of a digital
signal of a 0--1--0--1
…
stream.
Where Tcross1 and Tcross2 are the mean of the histogram of the two crossings. See NRZ
Crossings on page B--64.
If enabled, measurement gates constrain the measurement region to the area between the Start
Gate (G1) and Stop Gate (G2).
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 available.
NRZ Frequency
=
1
( 2
×
( Tcross2
−
Tcross1))
NRZ Period NRZ Period is twice the time interval between two consecutive eye-crossing points. It would be
the period of a digital signal of a 0--1--0--1
…
stream.
NRZ Period = 2 * (Tcross2 – Tcross1)
Where Tcross1 and Tcross2 are the mean of the histogram of the two crossings of the eye
diagram.
If enabled, measurement gates constrain the measurement region to the area between the Start
Gate (G1) and Stop Gate (G2).
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 available.