LeCroy 9300C Series, Руководство оператора

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D –8
Appendix D
P a r a m e t e r a n d w h a t i t d o e s Definition Notes
Threshold arguments specify two vertical
values on each edge used to compute fall
time. Formulas for upper and lower values:
lower value lower threshold
= × +
amp
base
100
upper value upper threshold
= × +
amp
base
100
first Indicates value of horizontal axis at left
cursor. Horizontal axis
value at left
cursor
(See Fig. D–2)
Indicates location of left cursor.
Cursors are interchangeable: for
example, the left cursor may be
moved to the right of the right
cursor and
first will give the
location of the cursor formerly
on the right, now on left.
freq Frequency: Period of cyclic signal
measured as time between every other
pair of 50 % crossings. Starting with first
transition after left cursor, the period is
measured for each transition pair. Values
then averaged and reciprocal used to
give frequency. 1/ period
(See Fig. D–2)
last
Time from trigger to last (rightmost)
cursor. Time from
trigger to last
cursor
(See Fig. D–2)
Indicates location of right cursor.
Cursors are interchangeable: for
example, the right cursor may
be moved to the left of the left
cursor and
first will give the
location of the cursor formerly
on the left, now on right.