Teledyne SP Devices ADQ7DC, Manual

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2019-02-01
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ADQ7DC Manual
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4.4.2 Block triggers once
The mode for blocking triggers once is illustrated in Figure 7 (j). This mode is used for starting the oper-
ation simultaneously in several units. The first time the trigger blocking signal is applied, the triggers are
allowed through. Here is the motivation for this mode:
There is no way to broadcast a software command to several units. When setting up acquisition in sev-
eral units, they will therefore be activated at different times. By using the trigger blocker, an electrical
signal to all units can activate them simultaneously. The trigger blocking signal can be external or it can
be generated internally using the bussed connections proposed in
Figure 13 .
4.4.3 Windowing triggers
The window mode for blocking triggers is illustrated in Figure 7 (k). The edge of the trigger blocking sig-
nal is activating a window of user-defined length which allows triggers through. There is also a mode
where triggers are blocked during the window.
The window mode can be used for two-dimensional triggering where, for example, the trigger signal is a
point trigger and a sync signal is a line trigger.
4.4.4 Gating and windowing triggers
The gate mode for blocking triggers is illustrated in Figure 7 (l). The length of the window where trig-
gers are accepted is equal to the length of the trigger blocking signal.
4.4.5 Programming sequence for using trigger blocking
The order of commands is important when programming the trigger blocking. This is because the ADQ
digitizer interact with other external equipment. This external equipment is synchronized to the digitizer
through the setup procedure.
The setup of the functions has to be aligned with the expected operation. For example, by asserting the
trigger blocking through the
SetupTriggerBlocking
command before setting up the acquisition, no trig-
gers are let through before the digitizer is ready.
# DESCRIPTION USER COMMAND REF
a The trigger blocker in window or gate mode allows triggers during a
certain period. SetupTriggerBlocking 4.4.1
b Example of rejected triggers outside the window.
c Trigger within the window is accepted and a data record is recorded.
Note that the pretrigger starts before the window.
d Trigger within the window is accepted and a data record is recorded.
Note that the record extends after the window.
e Several triggers within the same window.
Figure 8: Trigger blocker examples.
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