ADLINK PCI-9820 - Manual (Page 33)

Operation Theory
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Figure 4.5 Middle trigger
Like pre-trigger mode, the stored data may be less than the amount specified
if the trigger event occurs before the specified amount of data (M) has been
acquired. Users can also set by program to ignore trigger signals until the
specified amount of data (M) has been acquired.
4.3.4 Delay-trigger Acquisition
Use delay trigger acquisition to delay the data collection after the trigger
event, as illustrated in Fig 4.6. The delay time is specified by a 32-bit counter
value so that the maximum delay time is the period of timebase * (2
32
–1),
while the minimum delay time is the period of timebase.
Figure 4.6 Delay trigger
4.3.5 Post-trigger of Delay-trigger Acquisition with Re-trigger
Use post-trigger or delay-trigger acquisition with re-trigger function to collect
data after several trigger events, as illustrated in Fig 4.7. Users can program
the number of triggers then the PCI-9820 will acquire an additional record
each time a trigger is accepted until all the requested records have been
Acquired & stored
data with the speci-
fied amount (M)
Time
Operation
start
Trigger
event
Acquired & stored
data with the speci-
fied amount (N)
Acquired & stored
data with the speci-
fied amount
Time
Trigger
event
Operation
start
Acquisition
stop
Acquisition
start
Delay