Keithley KPCI-3101 Series, Руководство пользователя

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KPCI-3101 — KPCI-3104 Series User’s Manual Principles of Operation 2-23
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 2-20 for more informa-
tion on the external C/T clock source.
Using DriverLINX 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 2-21 for
more information on gate types.
Ensure that the signals are wired appropriately. Figure 2-10 shows one example of connecting an
event counting application to the STA-300 screw terminal panel using user counter 0. In this
example, rising clock edges are counted while the gate is active.
Figure 2-10
Connecting event counting signals (shown for clock input 0 and external gate 0)
STA-300
Panel
TB26
Signal Source
Digital Ground
User Clock Input 0
TB29
TB28
Digital Ground
Gate 0
External
Gating
Switch*
TB25
*An internal 22 k
Ω
pull-up resistor to +5V is used.