©
National Instruments Corporation
G-1
LabWindows/CVI PID Control Toolkit User Manual
Glossary
A
algorithm
A prescribed set of well-defined rules or processes for the solution of a
problem in a finite number of steps.
autotuning
Automatically testing a process under control to determine the controller
gains that will provide the best controller performance.
Autotuning Wizard
An automated graphical user interface provided in the Autotuning
functions. The Autotuning Wizard gathers some information about the
desired control from the user and then steps through the PID autotuning
process. You must specify to use wizard-based autotuning in
PidCreateWithAutotune
to use this feature.
B
bias
The offset added to a controller’s output.
bumpless transfer
A process in which the next output always increments from the current
output, regardless of the current controller output value. Therefore, transfer
from automatic to manual control is always bumpless.
C
cascade control
Control in which the output of one controller is the setpoint for another
controller.
closed loop
A signal path that includes a forward path, a feedback path, and a summing
point and that forms a closed circuit. Also called a
feedback loop
.
controller
Hardware and/or software used to maintain parameters of a physical
process at desired values.
controller output
A quantity or condition that is varied as a function of the actuating error
signal so as to change the value of the directly controlled variable.
cycle time
The time between samples in a discrete digital control system.
