17-2000 C
2020-09-17
16(50)
ADQ8-8C Manual
17-2000 C 2020-09-17
16(50)
4.5 Blocking triggers for synchronization
4.5.1
Function overview
In order to synchronize the acquisition to external equipment or to other ADQ digitizers, there is a
mechanism for controlling the flow of triggers. The trigger blocking function allows the user to select
when to activate incoming triggers,
. The basic function of this block is to use the SYNC signal
to frame the trigger signals; for each period of the blocking function, a set of triggers are allowed and
and framed by the blocking event. This creates groups of triggers that belong together. The modes of
operation for trigger blocking are shown in
(j, k, l).
To avoid that the boards start to produce a large amount of records out of sync, all trigger events can be
blocked until the triggers are released by a separate shared signal,
(d). By combining the trig-
ger blocking and the timestamp reset, the timestamp is aligned to the start of the acquisition. The trig-
ger blocker source can be most available trigger sources,
(a, b, c).
Note the order of the commands for activating triggers and trigger blockers,
(e, g, h, i).
#
DESCRIPTION
USER COMMAND
REF
a
External trigger input signal on front panel connector.
b
External sync input signal on front panel connector.
c
Other available sources (see
SetTriggerMode
for a list)
d
Select source for reseting timestamp.
SetupTimestampSync
DisarmTimeStampSync
ArmTimeStampSync
e
Timestamp counter value is reset at power-up of the digitizer.
f
Reset the timestamp counter on each pulse of the selected source.
Timestamp is then measuring time relative the previous reset signal.
g
h
Reset the timestamp counter only on the first pulse of the selected
signal. The external signal is then a systems synchronization signal.
i
The number of times the time stamp has been reset can be read from
a register.
GetTriggerBlockingGate
Count
Figure 7: Timestamp reset from external trigger.
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