6-1
IM DLM3054-01EN
6 Waveform Acquisition
Based on the data that has been stored in the acquisition memory, the instrument performs various operations,
such as displaying waveforms on the screen, computing, measuring cursors, and automatically measuring
waveform parameters.
This chapter explains how to set the number of data points to store in the acquisition memory (the record length),
how to enable or disable the sample data averaging feature, and so on.
Record length (Record Length)
Record length
refers to the number of data points that are stored to the acquisition memory for each channel.
Display record
length refers to the data points from the data stored in the acquisition memory that are displayed
on the screen. Normally, the acquisition-memory record length and display record length are the same, but the
time scale may cause them to differ.
When you change the time scale, the sample rate and record length also change.
The instrument allows you to set the record length to a value from 1.25 kpoints to 500 Mpoints (this range varies
depending on the installed option).
If you want to observe a long-term phenomenon at a high time resolution (at a high sample rate), set the record
length to a high value.
When the record length is long, computation and measurement processing take longer than when the record
length is short.
The following limitations on waveform acquisition conditions and the number of waveforms that can be stored in
the acquisition memory (the number of history waveforms) apply depending on the specified record length.
Record Length
Number of History Waveforms
No options
(125 Mpoints)
/M1 option
(250 Mpoints)
/M2 option
(500 Mpoints)
1.25 kpoints
20000
50000
100000
12.5 kpoints
2500
5000
10000
125 kpoints
250
500
1000
1.25 Mpoints
25
50
100
2.5 Mpoints
10
25
50
5 Mpoints
5
10
25
12.5 Mpoints
1
5
10
25 Mpoints
1
1
1
2
50 Mpoints
1
2
1
1
1
125 Mpoints
1
2, 3
1
2
1
1
250 Mpoints
−
1
2, 3
1
2
500 Mpoints
−
−
1
2, 3
1 Waveform acquisition operates in Single mode at this record length regardless of the trigger mode
setting. You cannot specify Envelope.
2 Waveform acquisition operates in Single mode at this record length regardless of the trigger mode
setting. You cannot specify Envelope, Averaging, or Interpolation mode.
3 CH2 and CH4 (LOGIC) waveforms cannot be acquired at this record length. Math2 (Ref2) and Math4
(Ref4) are also unavailable.