Measuring Waveforms
3-76 CSA8000B & TDS8000B User Manual
The following exclusions apply when using automatic measurements:
HMore than eight measurements at one time are not allowed.
HExcept for Average Optical Power, all measurements of the category RZ or
NRZ must be performed on a waveform database (see Use Databases as
Sources on page 3--75). The Average Optical Power measurement cannot use
a waveform database as its source.
HThe Average Optical Power measurement cannot display Annotations (see
page 3--74) and cannot use gates or user-defined High/Low methods (see
page 3--77).
HIf the waveform parameter that is to be automatically measured cannot be
acquired (incorrect control setup, out-of-range input signals), this instrument
displays the indicator “???.”For example, if the instrument acquires less
than a full waveform cycle, it cannot measure frequency or period and
displays ???.
The key points that follow describe operating considerations for setting up
automatic measurements to obtain the best measurement results.
Measurement Selection. The instrument takes automatic measurements of the
following categories: Amplitude, Timing, and Area. Check Appendix B:
Automatic Measurements Supported for a listing of the measurements that you
can choose from in each signal type category.
Number of Measurements. The instrument can take and update up to eight
measurements at one time. You can apply measurements to any combination of
sources (described below). You can take all eight measurements on C1, for
example, or one measurement each on C1 -- C8.
Measurement Sources. All channel, reference, and math waveforms can serve as
sources for automatic measurements. You can also measure any of the four
waveform databases that the instrument supports. You can specify a waveform as
source in the Meas Setup dialog box even if the waveform is not displayed.
Some measurements, such as Gain, Delay, and Phase, require two sources. For
example, Gain would be used to measure an input from one measurement source
(such as C1) with respect to an output in another source (such as C2).
Databases as Sources Behavior. Consider the following operating behaviors
regarding measurements and databases:
HWhen enabling a measurement, it will always measure the waveform
database if the measurement source you choose is currently displayed as a
What’s Excluded?
Keys to Using