Data Translation DT9800 Series, Руководство пользователя

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Principles of Operation
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Counter/Timer Operation Modes
DT9800 Series function modules support the following counter/timer
operation modes:
• Event counting,
• Frequency measurement,
• Rate generation,
• One-shot, and
• Repetitive one-shot.
The following subsections describe these modes in more detail.
Event Counting
Use event counting mode to count events (clock pulses) from the
counter’s associated clock input source.
If you are using one counter, you can count a maximum of 65,536
events before the counter rolls over to 0 and starts counting again. If
you are using a cascaded 32-bit counter, you can count a maximum of
4,294,967,296 events before the counter rolls over to 0 and starts
counting again.
In event counting mode, use an external C/T clock source; refer to
page 47 for more information on the external C/T clock source.
Using software, specify the counter/timer mode as event counting
(count), the C/T clock source as external, and the gate type that
enables the operation as logic high. Refer to
page 51 for information
on gates.
Ensure that the signals are wired appropriately. Refer to the DT9800
Series Getting Started Manual for wiring examples.