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National Instruments Corporation
11
BNC-2121 Connector Accessory for 660X Devices
Buffered Event Counting
To perform buffered event counting, complete the following steps.
1.
In the C interface or in LabVIEW, select an internal timebase as
SOURCE of the selected counter.
2.
Connect a wire from the
spring terminal to GATE of the selected
counter. Each time GATE goes high, the value of the counter is latched
to a buffer.
Buffered Period Measurement
To perform buffered period measurement, complete the following steps.
1.
In the C interface or in LabVIEW, select an internal timebase as
SOURCE of the selected counter.
2.
Connect a wire from the
spring terminal to GATE of the selected
counter.
Note
To ensure valid measurement data, discard the first value because the counter may
be armed between active edges. The counter is latched at each active GATE edge (rising or
falling) and the counter resets to zero.
Buffered Semi-Period Measurement
To perform buffered semi-period measurement, complete the following
steps.
1.
In the C interface or in LabVIEW, select an internal timebase as
SOURCE of the selected counter.
2.
Connect a wire from the
spring terminal to GATE of the selected
counter.
Each time GATE goes high, the value of the counter is latched to a buffer.
Because buffered semi-period measurement measures each phase of the
pulse train, you can detect changes in duty cycle.
Note
To ensure valid measurement data, discard the first value because the counter may
be armed between active edges. The counter is latched at each active GATE edge (rising or
falling) and the counter resets to zero.
