Retriggerable Pulse Or Pulse Train Generation - National Instruments DAQ X Series User Manual

Chapter 7 Counters

Retriggerable Pulse or Pulse Train Generation

The counter can output a single pulse or multiple pulses in response to each
pulse on a hardware Start Trigger signal. The generated pulses appear on
the Counter n Internal Output signal of the counter.
You can route the Start Trigger signal to the Gate input of the counter. You
can specify a delay from the Start Trigger to the beginning of each pulse.
You also can specify the pulse width. The delay and pulse width are
measured in terms of a number of active edges of the Source input. The
initial delay can be applied to only the first trigger or to all triggers using
the CO.EnableInitalDelayOnRetrigger property. The default for a single
pulse is True, while the default for finite pulse trains is False.
The counter ignores the Gate input while a pulse generation is in progress.
After the pulse generation is finished, the counter waits for another Start
Trigger signal to begin another pulse generation. For retriggered pulse
generation, pause triggers are not allowed since the pause trigger also uses
the gate input.
Figure 7-31 shows a generation of two pulses with a pulse delay of five and
a pulse width of three (using the rising edge of Source) with
CO.EnableInitalDelayOnRetrigger set to the default True.
Counter
Load Values 4 3 2 1 0 2 1 0 4 3 2 1 0 2 1 0
GATE
(Start Trigger)
SOURCE
OUT
5 3 5 3
Figure 7-31. Retriggerable Single Pulse Generation with Initial Delay on Retrigger
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