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National Instruments Corporation
5-1
5
Counters
Figure 5-1 shows a counter on the E Series device.
Figure 5-1.
Counter Block Diagram
Counters 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
Counter Triggering
Counters support two different triggering actions: start and pause. A digital
trigger can directly initiate these actions. An analog trigger can indirectly
initiate these actions by routing the Analog Comparison Event from a
triggered analog input or output task to the counter as a digital trigger.
Start Trigger
A start trigger begins a finite or continuous pulse generation. Once a
continuous generation is initiated, the pulses continue to generate until you
stop the operation in software. The specified number 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.
Source
Out
Gate
Software Registers