Table Of Contents
PID (PID » Academic) (G Dataflow)
Implements a PID controller in the Academic form.
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feedforward input
Value of the feedforward control.
This input accepts an array of double-precision, floating-point numbers if setpoint is an array.
manual control
Settings for the manual control mode.
This input accepts an array of clusters if setpoint is an array.
manual
manual input
Value of the control output when you use the manual control mode.
Default: 0
reset
A Boolean that specifies whether to reset the internal parameters, such as the integrated error, of the controller.
| True | Resets the internal parameters. |
| False | Does not reset the internal parameters. |
Set reset to True if your application must stop and restart the control loop without restarting the entire application.
This input accepts an array of Booleans if setpoint is an array.
Default: False
setpoint
Setpoint value, or desired value, of the process variable.
This input accepts a double-precision, floating-point number or an array of double-precision, floating-point numbers.
process variable
Measured value of the process variable.
This input accepts an array of double-precision, floating-point numbers if setpoint is an array.
PID gains
Proportional gain, integral gain, derivative gain, and filter coefficient parameters of the controller.
This input accepts a cluster or an array of clusters.
proportional
Proportional gain of the controller.
integral
Integral time constant of the controller, in seconds.
derivative
Derivative time constant of the controller, in seconds.
filter coefficient [a]
Derivative lowpass filter coefficient of the controller.
output range
Range for the control output value.
If the control output value is outside output range, this node coerces the value to fall within the range and returns the coerced value as the control output value. This node implements integrator anti-windup when the control output is saturated at the specified minimum or maximum value.
This input accepts an array of clusters if setpoint is an array.
output high
Maximum control output value.
Default: Infinity
output low
Minimum control output value.
Default: -Infinity
dt
Loop-cycle time, or interval in seconds, at which this node is called. dt must be greater than 0.
setpoint weighting
Corrections to apply to the error values of the controller. setpoint weighting tunes the proportional action and the derivative action.
This input accepts an array of clusters if setpoint is an array.
proportional weighting [beta]
Relative emphasis of setpoint tracking to disturbance rejection.
The valid value range is [0, 1]. Use the default value for most applications.
Default: 1
derivative weighting [gamma]
An amount by which to weight the error applied to the derivative action.
The valid value range is [0, 1]. Use the default value to avoid the derivative kick.
Default: 0
output
Control output of the PID algorithm that is applied to the controlled process.
error
Difference between the setpoint and the process variable.
actions
Values of the proportional action, the integral action, and the derivative action in the PID algorithm.
proportional
Value of the proportional action.
integral
Value of the integral action.
derivative
Value of the derivative action.
Algorithm Definition
The following transfer function represents a PID controller in the Academic form:
where
- Kc is the proportional gain
- Ti is the integral time constant
- Td is the derivative time constant
- is the derivative filter coefficient
Where This Node Can Run:
Desktop OS: Windows
FPGA: This product does not support FPGA devices
Web Server: Not supported in VIs that run in a web application