Tektronix WCA200A, User Manual

Page: 268 / 454

Setting Timing Parameters
3- 142
WCA230A & WCA280A User Manual
The Timing menu in Demod (modulation analysis) and Time (time analysis)
modes contains the following items (see Figure 3--97):
Acquisition Length. Sets the time length to acquire one block (= M frames).
The acquisition length is calculated using this equation:
(One block acquisition length) = M
×
(One frame acquisition length)
where M is the number of frames in a block.
One frame acquisition length is determined by span internally. For details, refer
to Table A--10 on page A--8 in Appendix A: Specifications.
Acquisition History.
Specifies the number of the block to display and analyze.
The latest block is number zero. Older blocks have larger negative numbers.
In most cases the analyzer retains previous acquisitions. You can view previous
acquisitions by selecting the acquisition history by block number.
Spectrum Length. Displays the time length for FFT processing of the spectrum
displayed in the subview. It is equivalent to one frame acquisition length
determined by Span, RBW, and FFT points setting.
Spectrum Offset. Sets the beginning of Spectrum Length with respect to the
trigger output point.
Analysis Length. Sets the time length of the analysis range in the block
specified by Acquisition History.
Analysis Offset. Sets the beginning of Analysis Length with respect to the
trigger output point.
Output Trigger Indicator. Determines whether to display the output trigger
indicator (“O”) on the overview. Refer to Trigger Point Indicator on page 3--171.
For procedures to set these parameters, refer to Setting the Analysis Range on
page 3--30 and
Setting FFT Processing Range for the Subview
on page 3--34.
Timing Parameters in
Demod and Time Modes