1-12
IM 701830-01E
1.4
Setting the Acquisition and Display Conditions
Record Length
≡
Page 7-1.
≡
Normally, the term record length refers to the number of data points acquired in the acquisition
memory per channel. Display record length refers to the number of these data points that are
actually displayed on the screen. The sample rate and record length vary according to the time
axis setting (refer to page 1-2). This instrument allows the record length to be selected from the
following choices: 1 kW, 10 kW, 40 kW, 100 kW, 200 kW, 400 kW, 1 MW, 2 MW, 4 MW, 8
MW, 16 MW, 32 MW, and 64 MW (The maximum record length that can be selected depends
on the options).
In most cases the displayed record length is identical to the (acquisition) record length. For
certain time-axis settings, however, the lengths become different. For details, refer to Appendix
1.
To observe all of the data when the display record length is shorter than the set record length,
move the horizontal position of the horizontal zoom function. For details, refer to Section 8.9
“Zooming the Waveform.”
Acquisition Modes
≡
page 7-2.
≡
When storing sampled data in the acquisition memory, it is possible to perform processing on
specified data and display the resultant waveform. The following data processing methods are
available.
Normal mode
In this mode, sampled data are stored in the acquisition memory without processing.
Averaging mode
Averaging is a process in which waveforms are acquired repeatedly to obtain the average of
waveform data of the same timing (the same time in relation to the trigger point).
If this mode is active, the instrument takes the linear or exponential average of incoming data
and writes the results into acquisition memory. The averaged data is then used to generate the
display. You can set the attenuation constant to a value from 2 to 256 (in 2
n
steps), and the
averaging count to a value from 2 to 65536.
An = {(N - 1)A
n - 1 +
X
n
}
1
N
Exponential averaging (count = Infinite)
A
N
=
N
Linear averaging (count = 2 to 65536)
N
n=1
Σ
X
n
An
Xn
N
: Value obtained after nth averaging
: nth measured value
: Attenuation constant
(2 to 256,in steps of 2
n
)
Xn
N
: nth measured value
: Number of averaging times
(Acquisition count,
in steps of 2
n
)
This averaging process is useful when you want to eliminate random noise.
Sequentical Store
Refer to page 1-13.
