Enabling Duplicate Count Prevention In Ni-Daqmx - National Instruments Data Acquisition Device NI USB-621x User Manual

Gate
Source
80 MHz Timebase
Counter Value
Buffer
© National Instruments Corporation
6 7 0
7
Figure 8-33. Duplicate Count Prevention Example
Even if the Source pulses are long, the counter increments only once for
each Source pulse.
Normally, the counter value and Counter n Internal Output signals change
synchronously to the Source signal. With duplicate count prevention, the
counter value and Counter n Internal Output signals change synchronously
to the 80 MHz Timebase.

Enabling Duplicate Count Prevention in NI-DAQmx

Duplicate count prevention is automatically used with USB-621x devices.
Disabling duplicate count prevention is not supported.
Counter detects
rising Gate edge.
0
7
8-37
Chapter 8
Counter value
increments only
one time for each
Source pulse.
1
NI USB-621x User Manual
Counters