Tektronix 2221 - Page 39

Controls
,
Connectors
, and
Indicators
- 2221
Operators
П
П
1
П
o
Table
3-2
2221 Digital Storage Modes
Trig
Mode
Selected SEC /
DIV
Setting
Acquisition
Mode
Storage
Mode
Displaya
0.05
us
/ div to
2 us / div
All
REPETITIVE
Dots
AVERAGED
SAMPLE
ACCPEAK
5 us / div to 10 us / div
All
FAST RECORD
Vector /
Dots
SAMPLE
ACCPEAK
AVERAGES
20 us / div to 50 ms / div
All
SLOW RECORD
Vector / Dots
PEAK
DETECT
ACCPEAK
SAMPLE
AVERAGED
NORM
SCAN
Vector / Dots
0.1 s /
div to 5 s
/ div
or EXT CLOCK to
1
kilosample /
sec (
cont
)
PEAK
DETECT
ACCPEAK
SAMPLE
AVERAGE
PEAK DETECT
SAMPLE
ROLL
Vector /
Dots
P - P
AUTO or
SGL SWP
In X - Y
mode
, the
Display
mode
is
always
Dots .
bThe
AVERAGE
mode
weight is
1/16 .
SEC / DIV switch ( increases the slowest NON - STORE
Sweep time per division to at least 2 s ) .
П
П
Л
n
n ?
1
Л
ก
П
1
Л
П
AVERAGE
Acquisition mode is
used for
multiple
record averaging . A normalized algorithm continu
ously displays the signal at full amplitude during
the
averaging
process
.
The
averaging weight ( the
number
of
weighted waveform acquisitions
included
in
each
average display ) is 1/16
. The
averaging
process
is reset by
changing
any
con
trol that causes an acquisition reset .
The Variable SEC / DIV control does not affect the
STORE time base
for
acquiring
signals
. If
rotated
out of the CAL detent position , the Variable
Table 3-3
Repetitive Store
Sampling Data
Acquisition
SEC / DIV
Switch
Setting
Samples
Per
Acquisition
Expected Acquisitions
Per
Waveforma
ACCPEAK Acquisition mode causes accumulation
of
peaks over
multiple
acquisitions . The
largest
maximum and
smallest
minimum
samples are
retained for each
trigger
-
referenced
acquisition
record
.
For 20 us
per
division to 5 s
per
division
,
hardware
peak
detection is
used
,
updating
max
imum and
minimum samples within each
time
base clock period . The ACCPEAK display is reset
by changing any control that causes an acquisi
tion reset
.
ACCPEAK
mode is valid
for
triggered
acquisitions only and is
not
operational in
untrig
gered
modes
.
One
Channel
Two
Channels
0.05
us
40 519 450
0.1
us
80
225
191
0.2
us
160 96
83
0.5
us
400 30
23
1
us
800 12
19 Variable SEC / DIV and DISPLAY COMPRESS
Control -
Continuously
varies the
uncalibrated
NON - STORE sweep time per division to at least 2.5
times the
calibrated time per
division
set by
the
2
us
800 12
11
C
aFor a 50 %
probability
of fill .
П
3-7