Tektronix CSA8000B Series, Руководство пользователя

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Appendix B: Automatic Measurements Reference
CSA8000B & TDS8000B User Manual
B- 31
Table B- 5: RZ Measurements - Timing (cont.)
Name Definition
RZ Delay The time interval between the crossings of the mid-reference levels on the two sources of the
measurement. The crossing times are computed as the mean of the histogram of the data slice
at the mid-reference level.
RZ Delay = Tcross(source1) – Tcross(source2)
Where Tcross is the mean of the histogram of a positive or negative crossing at
mid-reference level. See
RZ Crossings on page B--61.
The mid-reference level is adjustable and defaults to 50% of the RZ maximum pulse amplitude.
See
Mid-reference level on page B--69.
The slope can be selected to be the first positive, the first negative, or the first crossing (positive
or negative) in the region.
If enabled, measurement gates constrain the measurement region to the area between the Start
Gate (G1) and Stop Gate (G2). By default, for each source, the algorithm searches forward from
the Start Gate for the first rising or falling edge as defined by Slope, but the Direction of
traversal can be reversed, so that the search will be backward from the Stop Gate. 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.
RZ +Duty Cycle The ratio of the RZ pulse width to the RZ bit time.
If the first crossing is positive, then:
If the first crossing is negative, then:
Where Tcross1, Tcross2 and Tcross3 are the mean of the histogram of the first three
consecutive crossings at the mid-reference level.
The mid-reference level is adjustable and defaults to 50% of the RZ maximum pulse amplitude.
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.
Duty Cycle
=
( Tcross2
−
Tcross1)
( Tcross3
−
Tcross1)
Duty Cycle
=
( Tcross 3
−
Tcross 2)
( Tcross 3
−
Tcross 1)