ADLINK PCI-8124-C - Manual (Page 44)

34 Operation Theory
4.2 Trigger Board Operation
This section describes the operation theory for users to know
more about PCI-8124-C.
4.2.1 Position Comparison
The PCI-8124-C provides position comparison functions for each
channel. Once the counter reaches a preset value set by the user,
the PCI-8124-C will generate the trigger pulse. TRGx pins are for
trigger pulse output channels. Users can also choose TTL Output
pins for this purpose. TRG is an open collector pin.
The comparing method is “equal”. Consequently, when the coun-
ter value is exactly equal to the preset value by users, the trigger
pulse will be generated. At the same time, the next comparing
points saved in FIFO or linear function will automatically loaded
into comparator. The following is an example for continuous trigger
application.
Example: Using the continuous position comparison function.
In this application, the table is controlled by the motion command,
and the CCD Camera is controlled by the position comparison out-
put of the PCI-8124-C. An image of the moving object is easily
obtained.