4 position comparator trigger, Position comparator trigger – ADLINK PCI-9524 User Manual
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Operation
Theory
ADLINK Technology Inc.
Copyright 2008
the specimen-under-test to a certain level before the AI acquisition
starts.
For applications that do not need pulse-command channel #0, this
trigger source can be used to turn post-trigger mode to delay-trig-
ger mode; by specifying the pulse frequency and pulse count, and
starting the pulse-command generator, the AI acquisition starts
immediately after the duration pulse_counts x ( 1 /
pulse_frequency) has expired.
If re-trigger is enabled, users may re-start the pulse-command
generator and generate a new trigger, without first stopping the AI
acquisition. The AI acquisition accepts a new trigger and re-
starts, after the specified number of samples has been readily
acquired; else the trigger signal is ignored.
4.7.4
Position Comparator Trigger
The quadrate decoder has a built-in position comparator that gen-
erates an AD trigger signal whenever the counter value matches
the user specified one; that is, when the movement/displacement
crosses a physical point set by user. This trigger can be useful if it
is desired to start AI acquisition after the expected displacement is
reached.
Due to the nature of reversed rotation the decoder accepts, it is
possible to generate multiple AD triggers if the movement/dis-
placement is moving forth and back near the specified physical
point. If re-trigger is enabled, the AI acquisition re-starts after the
specified number of samples has been acquired; else the trigger
signal is ignored.