In implicit buffered semi-period measurements, on each edge of the Gate signal, the counter stores the count in the FIFO. The sampled values will be transferred to host memory using a high-speed data stream.
The counter begins counting when it is armed. The arm usually occurs between edges on the Gate input. You can select whether to read the first active low or active high semi-period using the CI.SemiPeriod.StartingEdge property in NI-DAQmx.
The following figure shows an example of an implicit buffered semi-period measurement.
For information about connecting counter signals, refer to the Default Counter/Timer Routing section.