5-5
IM DL35-01EN
• When the time base is External
• When the acquisition method is Memory, Save on Stop, or SD Numeric Recording
The acquisition length (Acquisition Length) is displayed. This is a function similar to the record length (Record
Length).
• When the acquisition method is SD Recording
The record length (Record Length) is displayed.
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.
In scope mode, on the standard model of the instrument, you can set the record length between 10 kpoint and
100 Mpoint. If you use SD recording, you can set the length to up to 5 Gpoint. For details about the record
lengths that can be set, see appendix 3 in the
Getting Started Guide
, IM DL350-03EN.
Use a long time scale when you want to observe a phenomenon over a long period of time. When you want to
observe a phenomenon at a high time resolution, set a long record length, and raise the sample rate. When
the record length is long, computation and measurement processing take longer than when the record length is
short.
The lengths of time for which you can record data to the acquisition memory when the record length is 100
Mpoint are listed below.
Sample Rate
In Seconds
In Minutes
In Hours
In Days
100 MS/s
1
10 MS/s
10
1 MS/s
100
100 kS/s
600
10
10 kS/s
6000
100
1 hour 40 min
1 kS/s
72000
12000
20
500 S/s
180000
3000
50
2 days 2 hours
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 set record length.
Notes about Setting the Record Length
• Increasing the record length automatically limits the number of channels that can be used. When some
channels are unavailable, the number of channels that can be used appears in the record length setup
menu.
• When the acquisition mode is set to Average, the maximum record length is 5 Mpoint.
• The maximum record length when SD recording is in use is 5 Gpoint (one channel).
• In the following situations, the record length cannot be set above 10 Mpoint.
• When the trigger mode is auto or normal
• When roll mode display is not in use
• On the instrument, record lengths are expressed in units of points. There are some products, such as the
DL750, for which record lengths are expressed in units of words.
5 Waveform Acquisition