Tektronix CSA8000B Series, Руководство пользователя

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Acquiring Waveforms
3- 34
CSA8000B & TDS8000B User Manual
Overview Control elements and resources To acquire in FrameScan mode (cont.)
Set the bit rate 8. Set the horizontal scale so one acquisition record is
equal to one bit. Use one of the two methods that follow:
H
Automatic: If your signal to be scanned matches a
communications standard, select it from the
Comm
Standard list. Choosing a standard sets the bit rate
and start bit; otherwise, if you know the bit rate, you
can set the bit rate manually using the Bit Rate
box.
H
Manual: Adjust the Scale control to a setting that
results in a display of both edges of the bit. For
example, setting 1/8 of a bit per division (0.125
bits/div) yields 1 bit in 8 divisions, which fits nicely
on screen.
Select a comm.
standard, or...
Set the bit rate
manually
Set to 1/8 bit
per division
Set the starting
horizontal posi-
tion
9. Set the initial horizontal position to the first bit you want
to acquire. Use one of the two methods that follow:
H
Automatic: Enter your desired start bit location, and
then check the
Auto Position box to enable the
instrument to set the position as near as possible to
match the bit specified in the
Start Bit box.
H
Manual: Adjust the Position control to align the
start of a bit to desired location in the frame.
Tip. The latter method is useful when you need to
manually align a bit or waveform to a mask on the
display.
Or set manually
First set the
start bit, ...
and then enable
Auto Position
Enable
FrameScan
10. In the dialog box, click to check the FrameScan
Enabled box. See right.
11. To restart the scan at the first bit at any time, click the
Reset button.
Click to
restart scan
Check to
start scan