Data Translation DT300 Series, Руководство пользователя, Страница: 98 / 164

Chapter 6
98
Refer to the following subsections for more information on these operation modes.
Event Counting
Use event counting mode to count events from the counter’s associated clock input source.
If you are using one counter, the board 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,
the board 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 95 for more
information on the external C/T clock source.
Using software, specify the counter/timer mode as event counting (count), the clock source as
external, and the gate type that enables the operation. Refer to
page 96 for more information
on gate types.
Ensure that the signals are wired appropriately. Figure 33 shows one example of connecting an
event counting application to the STP300 screw terminal panel using user counter 0. In this
example, rising clock edges are counted while the gate is active.
Figure 33: Connecting Event Counting Signals
(Shown for Clock Input 0 and External Gate 0)
STP300
Panel
TB26
Signal Source
Digital Ground
User Clock Input 0
TB29
TB28
Digital Ground
Gate 0
External
Gating
Switch*
TB25
*An internal 33 ohm series resistor is used.