NI cDAQ-9178 - Page 53

© National Instruments Corporation 53 NI cDAQ-9178/9174 User Guide and Specifications
• Finite Pulse Train Generation
• Retriggerable Pulse or Pulse Train Generation
• Continuous Pulse Train Generation
• Buffered Pulse Train Generation
• 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 NI cDAQ-9178/9174 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 47. Finite Pulse Train Generation: Four Ticks Initial Delay, Four Pulses
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.
Enablex
Source
Ctrx
Counter Armed