Measurement Computing Data Translation DT3034, Руководство пользователя

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Chapter 6
100
Figure 29: Example of a Low-to-High Pulse Output Type
Counter/Timer Operation Modes
DT3034 boards support the following counter/timer operation modes:
• Event counting
• Frequency measurement
• Rate generation
• One-shot
• Repetitive one-shot
The following subsections describe these modes in more detail.
Event Counting
Use event counting mode to count events 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 97 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. Refer to
page 99 for
information on gates.
Ensure that the signals are wired appropriately. Figure 30 shows one example of connecting an
event counting application. This example uses the DT740 screw terminal panel and user
counter 0; rising clock edges are counted while the gate is active.
Total Pulse Period
Active Pulse Width
low pulse
high pulse