Teledyne SP Devices ADQ7DC, Manual

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19-2233 PC2
2019-02-01
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ADQ7DC Manual
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4.2 Position of the trigger in the data
The trigger position relative to the data record is controlled by the parameters pretrigger and trigger
delay.
The pretrigger buffer enables capturing data prior to the trigger event,
Figure 4 . Use the command
Set-
PreTrigSamples
to define the pretrigger.
The trigger delay postpone the start of the acquisition of the data record specified number of samples
after the trigger event,
Figure 5 . Use the command
SetTriggerHoldOffSamples
to define the trigger
delay.
The timing of the trigger is read from the record header (
Section 7.6 ). The parameters
TIME_STAMP
and
RECORD_START
are explained in Section 4.3.1 .
4.3 Timestamp
4.3.1 Timestamp definitions
The timestamp counter enables real-time measurement of a trigger event. It is used for tagging an
event, sorting events in time or comparing timing between events.
The timestamp information consist of three parts, which uniquely defines the timing:
•
TIME_STAMP
measures the time of the trigger event relative to other trigger events.
•
RECORD_START
is the time between the trigger event and the start of the record. For a pretrigger,
this is a negative value. When trigger delay is used, this is a positive value.
Figure 4: Pretrigger timing.
Figure 5: Trigger delay timing.
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