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2-8
IM DL850-03EN
History
When waveforms are being measured, the waveform data stored in the acquisition memory as a result
of a trigger occurrence is displayed as a waveform on the DL850/DL850V screen and can be viewed.
When waveform acquisition is being triggered in succession and an abnormal waveform appears, it
is impossible to stop acquisition before a new waveform appears on the screen. Normally, it would be
impossible to view the abnormal waveform. However, with the history feature, you can view the past
waveform data (history waveforms) stored in the acquisition memory when waveform acquisition is
stopped. You can select specific history waveforms and display them.
You can also search through the history waveforms for waveforms that meet specified conditions.
• Zone Search
The DL850/DL850V searches for history waveforms that passed (or did not pass) through a
specified search zone.
• Waveform Parameter Search
The DL850/DL850V searches for waveforms whose measured waveform parameter values meet (or
do not meet) specified conditions.
History Waveforms
(up to 5000 waveforms)
Selected Record 0
Selected Record –25
Specified zone
Selected Record –28
Selected Record 0
History Waveforms
(up to 5000 waveforms)
Zone Search
Waveform parameter search
P-P
Waveforms that pass
through the specified
zone are detected.
Waveforms that do not
meet the specified
search parameter
conditions are detected.
Dual Capturing
You can use dual capturing to simultaneously record a trend at a low sampling speed in roll mode and
at a high sampling rate. This is useful for capturing fast phenomenon while observing a trend over a
long period of time.
Captured waveforms (high-speed sampling)
Update mode display
Main waveform (low-speed sampling)
Roll mode display
Captured
waveform
Zoomed waveform
(zoomed along the
time axis)
Main waveform
Sample rate:
Faster than that of
the main waveform
Sample rate:
100 kS/s or less
Because there is not
enough sampled data, the
shape of the waveform may
not be displayed correctly.
Because the data is sampled at
a high speed, the correct shape
of the waveform is displayed.
Events
The points where triggering
occurred during dual capturing
are displayed as events.
2.3 Waveform Acquisition