Chapter 4 General-Purpose Counter/TimerDAQ-STC Technical Reference Manual4-4 ©National Instruments Corporation4.4.1.1 Simple Event CountingIn simple event counting, the counter counts the number of pulses that occur on theG_SOURCE signal after the software arm. Software can read the counter contents at any timewithout disturbing the counting process. Figure 4-2 shows an example of simple eventcounting where the counter counts five events on G_SOURCE.Figure 4-2. Simple Event Counting4.4.1.2 Simple Gated-Event CountingSimple gated-event counting is similar to simple event counting except that the countingprocess is gated; that is, halted and resumed via G_GATE. When G_GATE is active, thecounter counts pulses that occur on the G_SOURCE signal after the software arm. WhenG_GATE is inactive, the counter retains the current count value. Figure 4-3 shows an exampleof simple gated-event counting where the gate action allows the counter to count only five ofthe pulses on G_SOURCE.Figure 4-3. Simple Gated-Event Counting4.4.1.3 Buffered Noncumulative Event CountingBuffered noncumulative event counting is similar to simple event counting except that thereare multiple counting intervals. The G_GATE signal indicates the boundary betweenconsecutive counting intervals. The counter counts the number of pulses that occur on theSoftware ArmG_SOURCECounter Value 10 5432Software ArmG_SOURCEG_GATECounter Value 10 5432
