7-6
IM 701830-01E
7.5
Using the History Memory
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For a description of this function, refer to page 1-14.
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Function
The acquisition memory retains waveform records generated by the most recent triggers. The
number of stored records is equivalent to the maximum number of records that can be obtained
when using sequential-store mode. Once the history becomes full, each new trigger causes loss
of the oldest waveform record in the memory.
Selected Record No.
You can display any waveform from the history by entering its record number. The newest
(current) waveform is Record 0, the immediately previous waveform is Record -1, and so on.
The range for Selected Record No. is therefore [0 to -(retained waveforms - 1)]. The number of
triggers that can be retained varies depending on the selected record length and acquisition
mode.
For details, refer to Appendix 2 “Relationship between the Record Length and Acquisition
Mode.”
Display
• Set to One to display the selected record only.
• Set to All to generate overlapped display of all history records from the Start Record No. to
the End Record No. The waveform corresponding to the Selected Record No. will appear
brighter than the other waveforms.
Show Map (List of time stamps)
You can list the numbers of the waveform data acquired in the acquisition memory and the
times of completion of the data acquisitions. The record number is displayed in 4 digits (record
number 0, -1, -2 are displayed as 0000, 0001, 0002, respectively).
Each page of the list shows information for 100 records. You use the Show Map No. setting to
select the page (map) to appear on the screen.
Precautions and Restrictions
• You cannot use the history function while the acquisition mode is set to Average. (Displayed
history records will be meaningless.)
• If you suspend waveform acquisition before the current record has been fully read, the record
will not be recorded in the history.
• You cannot use the history function together with the accumulation function.
• History records are not lost when waveform acquisition is stopped and then restarted,
provided that acquisition conditions remain unchanged.
• If you change the acquisition settings, history memory is cleared when you restart acquisition
using the new settings.
