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CHAPTER 3 Settings and Measurement
(4)-3 Pre-trigger
For pre-trigger, set the number of data points to record before trigger is set off.
* Pre-trigger can be selected only when the capturing destination is set to the internal RAM.
The data before the trigger point is called “pre-trigger data”, and the data after the trigger point is called
“post-trigger data”.
Initiate the ring capture for pre-trigger data before the trigger is set off.
When the trigger sets off, the capturing of the pre-trigger data is completed, the remaining post-trigger data
is captured and then completed.
Pre-trigger
Trigger points
Post-trigger
Pre-trigger points
Pre-trigger mode
Setting
Description
Prioritize trigger
When a trigger launches during pre-trigger, the pre-trigger capture is completed.
Prioritize pre-trigger capture
Trigger is not accepted until pre-trigger capture is completed.
Even if a trigger sets off, it is ignored.
< Prioritize trigger >
When a trigger launches during pre-trigger capturing, and capturing for the pre-trigger points has not
been completed, pre-trigger capture is completed at the time of trigger and post-trigger data is captured
immediately.
Below is the case when a trigger sets off before the capturing of the pre-trigger points is completed.
Pre-trigger
Pre-trigger points
Trigger points
Pre-trigger
Less than the
pre-trigger points
Not captured
Post-trigger
Capturing for post-trigger data starts immediately after
the trigger launches.
The total data after capturing is less due to the uncaptured pre-trigger point.
The pre-trigger data which could not be captured remains as is and the total number of data points is
reduced.
* When a trigger launches after completing the data corresponding to the pretrigger data points, there is no
uncaptured data.
