7-2
IM 701830-01E
7.2
Acquisition Mode
≡
For a description of this function, refer to page 1-12.
≡
Function
You can select any of five acquisition modes, as follows. The default selection is Normal.
Normal
The instrument writes sample data into acquisition memory without performing special
processing.
Average
The instrument calculates average values and writes these into the acquisition memory. If the
acquisition count is set to Infinite, the instrument uses exponential averaging, and you are
required to set a Weight value. If the count is set to a numerical value (from 2 to 65536), the
instrument calculates simple averages using the specified number of readings.
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
)
• Setting restrictions
If 16MW/CH model : You cannot select this mode if the record length is set 2 M or above
(when using 16 channels).
If 8MW/CH model : You cannot select this mode if the record length is set 1 M or above
(when using 16 channels).
If 2MW/CH model : You cannot select this mode if the record length is set 200 k or above
(when using 16 channels).
If 200kW/CH model : You cannot select this mode if the record length is set 40 k or above
(when using 16 channels).
For details on the maximum record length that allows roll mode and averaging, refer to
Appendix 1 “Relationship between the Time Axis Setting, Sample Rate and Record Length”
and Appendix 2 “Relationship between the Record Length and Acquisition Mode.”
Sequence (Sequential store)
For details, see Section 7.3.
Envelope
The instrument finds the maximum and minimum values from the data sampled at the maximum
sample rate of each module, writes these values into acquisition memory, and generates an
“envelope” waveform showing max/min levels for each point.
• Setting restriction
The setting is valid when the sample rate is 5 MS/s or less.
BoxAverage
For details, see Section 7.4.
Acquisition count
The available count settings are indicated below. If you set the value to Infinite, acquisition will
continue until you switch it off with the
START/STOP
key.
The default count is Infinite.
• Normal, Envelope, or BoxAverage mode:
2 to 65535 (in steps of 1), Infinite
• Average mode:
2 to 65536 (in 2
n
steps), Infinite
• Sequence mode:
(See Section 7.3.)
