Chapter 7 CountersM Series User Manual 7-22 ni.cominput. You also can specify the active edge of the Source input (rising orfalling).The counter can begin the pulse train generation as soon as the counter isarmed, or in response to a hardware Start Trigger. You can route the StartTrigger to the Gate input of the counter.You also can use the Gate input of the counter as a Pause Trigger (if it is notused as a Start Trigger). The counter pauses pulse generation when thePause Trigger is active.Figure 7-24 shows a continuous pulse train generation (using the risingedge of Source).Figure 7-24. Continuous Pulse Train GenerationContinuous pulse train generation is sometimes called frequency division.If the high and low pulse widths of the output signal are M and N periods,then the frequency of the Counter n Internal Output signal is equal to thefrequency of the Source input divided by M + N.For information about connecting counter signals, refer to the DefaultCounter/Timer Pinouts section.Frequency GenerationYou can generate a frequency by using a counter in pulse train generationmode or by using the frequency generator circuit.Using the Frequency GeneratorThe frequency generator can output a square wave at many differentfrequencies. The frequency generator is independent of the twogeneral-purpose 32-bit counter/timer modules on M Series devices.SOURCEOUTCounter Armed
