Finite Pulse Train Generation; Retriggerable Pulse Or Pulse Train Generation - National Instruments cRIO-904 Series User Manual

• Finite Implicit Buffered Pulse Train Generation
• Continuous Buffered Implicit Pulse Train Generation
• Finite Buffered Sample Clocked Pulse Train Generation
• Continuous Buffered Sample Clocked Pulse Train Generation

Finite Pulse Train Generation

This function generates a train of pulses with programmable frequency and duty cycle for a
predetermined number of pulses. With cRIO controller counters, the primary counter generates
the specified pulse train and the embedded counter counts the pulses generated by the primary
counter. When the embedded counter reaches the specified tick count, it generates a trigger
that stops the primary counter generation.
Figure 76. Finite Pulse Train Generation: Four Ticks Initial Delay, Four Pulses
Counter Armed
Source
Enablex
Ctrx

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.
The figure below 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.
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