National Instruments 6711 User Manual

Also see for DAQCard-6715: User manual User manual

Contents

National Instruments 6711 User Manual Manual pdf 45 page image

© National Instruments | 5-15CountersFigure 5-1 shows a counter on the AO Series device.Figure 5-1. Counter Block DiagramCounters 0 and 1 each have two inputs (source and gate), one output, and two software registers,which are used to perform different operations. Counter functionality is built into the DAQ-STC.For more information on the DAQ-STC, refer to the DAQ-STC section of Chapter 1, DAQSystem Overview.Counter TriggeringCounters support two different triggering actions: start and pause. Only digital triggers caninitiate these actions. For more information on digital triggers, refer to the Triggering with aDigital Source section of Chapter 10, Triggering.Start TriggerA start trigger begins a finite or continuous pulse generation. When a continuous generation isinitiated, the pulses continue to generate until you stop the operation in software. The specifiednumber of pulses are generated for finite generations unless the retriggerable attribute is used.The retriggerable attribute causes the generation to restart on a subsequent start trigger.Pause TriggerYou can use pause triggers in edge counting and continuous pulse generation applications. Foredge counting acquisitions, the counter stops counting edges while the external trigger signal islow and resumes when the signal goes high or vice versa. For continuous pulse generations, thecounter stops generating pulses while the external trigger signal is low and resumes when thesignal goes high or vice versa.SourceOutGateSoftware Registers