National Instruments PID Control Toolkit 371685C-01 User Manual page 28

The control loops can be timed in the following ways:
• Software-Timed—In software-timed control loops, the timing is controlled by the
software loop rate. You can implement a software loop with a timer construct, such as a
timer control or asynchronous timer, or a while loop with a delay or sleep operation at
the end.
• Hardware-Timed—In hardware-timed control loops, the timing is controlled by the
DAQ device. The DAQ device is configured with the appropriate sample rate, and the
sample mode is set to hardware-timed.
For more information about DAQ, refer to the NI-DAQmx Help or Traditional NI-DAQ
(Legacy) C Function Reference Help, depending on the DAQ API you are using. Also refer
to the DAQ example programs.
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Chapter 3
3-11 LabWindows/CVI PID Control Toolkit User Manual
Using the PID Control Toolkit