YOKOGAWA ScopeCorder DL350, Руководство пользователя

Страница: 97 / 258

5-9
IM DL35-01EN
Acquisition Settings (Acquisition Setup)
There are acquisition settings.
•
Acquisition Mode (Acquisition Mode)
• Acquisition Count (Acquisition Count)
Acquisition Mode (Acquisition Mode)
Select from the following.
Normal Mode (Normal)
Displays waveforms without processing the sampled data.
Envelope Mode (Envelope)
The instrument determines the maximum and minimum values among the data sampled at the maximum
sample rate for each module at a time interval that is twice the sampling period (the inverse of the sample rate)
of Normal mode, saves the values as pairs in the acquisition memory, and uses the saved value pairs to display
the waveforms. This mode is effective when you want to avoid aliasing, because the sample rate is essentially
kept high regardless of the time scale. It is also effective when you want to detect glitches (narrow pulse signals)
or when you want to display the envelope of a modulated signal.
Envelope mode
Normal mode
Averaging Mode (Average)
The instrument acquires waveforms multiple times, averages the same time points relative to the trigger point,
saves them in the acquisition memory, and uses them to display averaged waveforms. Averaging mode is useful
when you want to remove random noise from waveforms.
The averaging method varies depending on the acquisition count.
An = {(N–1)A
n–1
+ X
n
}
1
N
An
Xn
N
: nth
th
averaged value
: nth
th
measured value
: Attenuation constant
(2 to 256 in 2n
n
steps)
A
N
= N
N
n = 1
Σ X
n
Xn
N
: nth
th
measured value
: Average count = acquisition count
Linear average Exponential average
When Acquisition Count Is
Set to Infinity
When Acquisition Count Is
Set to a Value between 2
and 65536 (in 2n n steps)
• When waveforms are acquired in averaging mode, they are saved to the acquisition memory as a single
record. This means that the history feature cannot be used.
• You cannot select averaging mode when:
• The display is in roll mode.
• The trigger mode is Single or On Start.
• SD recording is being executed.
• Waveforms of logic, CAN bus monitor, LIN bus monitor, or SENT monitor modules cannot be averaged.
5 Waveform Acquisition