© National Instruments | 5-23NI cDAQ-9138/9139 User ManualFigure 5-23 shows an example of a single two-signal edge-separation measurement.Figure 5-23. Single Two-Signal Edge-Separation MeasurementImplicit Buffered Two-Signal Edge-Separation MeasurementImplicit buffered and single two-signal edge-separation measurements are similar, but implicitbuffered measurement measures multiple intervals.The counter counts the number of rising (or falling) edges on the Source input occurring betweenan active edge of the Gate signal and an active edge of the Aux signal. The counter then storesthe count in the FIFO. On the next active edge of the Gate signal, the counter begins anothermeasurement. The STC3 transfers the sampled values to host memory using a high-speed datastream.Figure 5-24 shows an example of an implicit buffered two-signal edge-separation measurement.Figure 5-24. Implicit Buffered Two-Signal Edge-Separation MeasurementSample Clocked Buffered Two-Signal Separation MeasurementA sample clocked buffered two-signal separation measurement is similar to single two-signalseparation measurement, but buffered two-signal separation measurement takes measurementsover multiple intervals correlated to a sample clock. The counter counts the number of rising (orfalling) edges on the Source input occurring between an active edge of the Gate signal and anactive edge of the Aux signal. The counter then stores the count in the FIFO on a sample clockedge. On the next active edge of the Gate signal, the counter begins another measurement. TheSTC3 transfers the sampled values to host memory using a high-speed data stream.Figure 5-25 shows an example of a sample clocked buffered two-signal separationmeasurement.AUXCounterArmed80 0 0 1 2 3 4 5 6 7 8 80 8Measured IntervalGATESOURCECounter ValueLatched ValueSOURCECounter ValueBufferAUXGATE1 2 3 1 2 3 1 2 33 33333
