4 trigger comparator, Trigger comparator – ADLINK PCI-8154 User Manual

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Operation Theory

4.6.4

Trigger comparator

The trigger comparator is much like general comparator. It has an
additional function, generating a trigger pulse when condition is
met. Once the condition is met, the CMP pin on the connector will
output a pulse for specific purpose like triggering a camera to
catch picture. Not all of axes have this function. It depends on the
existence of CMP pin of the axis. The following diagram shows the
application of triggering.

In this application, the table is controlled by the motion command,
and the CCD Camera is controlled by CMP pin. When the compar-
ing position is reached, the pulse will be outputted and the image
is captured. This is an on-the-fly image capture. If users want to
get more images during the motion path, try to set a new compar-
ing point right after previous image is captured. It can achieve con-
tinuous image capturing by this method.

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