FB_PressureControlParams_PID

This function block contains a parameter set to be used by a FB_PressureControl_PID function block.

Syntax:

FUNCTION_BLOCK FB_PressureControlParams_PID

Properties

Name	Type	Access	Properties
ChangeRate	LREAL	Get, Set	The ramp rate used in pressure units per second (typ. [bar/s]). Further notes at `EnableChangeRate`.
Enable	BOOL	Get, Set	This property is used to activate and disable the proportional component of the PID controller. Further notes at `Kp`.
EnableChangeRate	BOOL	Get, Set	Enables a setpoint ramp function. The internally used setpoint for the control can be updated to the specified setpoint at a limited rate, specified as `ChangeRate`. A setting of `ChangeRate=0.0` or `EnableChangeRate=FALSE` disables the ramp function and causes the internal setpoint to immediately follow the specified setpoint.
EnableOutputLimit	BOOL	Get, Set	Enables a limiting function for the output of the controller (manipulated variable). Further notes at `OutputLimit`.
EnableD	BOOL	Get, Set	Enables the differential component of the PID controller. Further notes at `Td`.
EnableFeedForward	BOOL	Get, Set	Enables the velocity feedforward control. Further notes at `FeedForward`.
EnableI	BOOL	Get, Set	Enables the integrating part of the PID controller. Further notes at `Tn`.
EnableNeg	BOOL	Get, Set	Enables a negative output of the controller.
EnablePos	BOOL	Get, Set	Enables a positive output of the controller.
EnableProfile	BOOL	Get, Set	Enables the use of the setpoint profile via `PID.PressureLookUp` Preliminary implementation
FeedForward	LREAL	Get, Set	Feedforward values for velocity feedforward control. If `EnableFeedForward` is set to `TRUE`, the value of `FeedForward` is multiplied by `FeedForwardFactor` and added to the PID response output. In the case of back pressure control, the reverse velocity of the injector can be adapted to the effect of the dosing axis using feedforward control. This can make a positive contribution to the control quality when dynamically adjusting the dosing speed.
FeedForwardFactor	LREAL	Get, Set	Gain factor for the velocity feedforward control. Further notes at `FeedForward`.
Kp	LREAL	Get, Set	The proportional gain of the PID controller. `Enable` must be `TRUE` to release the effect. The value is measured in velocity unit per pressure unit (typically [mm/s / bar].
OutputLimit	LREAL	Get, Set	Limitation for the output of the controller.
Reversed	BOOL	Get, Set	Reverses the output of the PID controller. In some use cases, the axis must move in the positive direction to relieve pressure. A typical example is holding pressure and back pressure control in injection molding machines.
Td	LREAL	Get, Set	The differential component of the PID controller. The value is measured in velocity units multiplied by seconds per pressure unit (typically [mm/ss/bar]) The response is calculated if* `EnableD=TRUE` and `Td` and `Tdd>=CycleTime`, otherwise it is `0`.
Tdd	LREAL	Get, Set	Attenuation of the differential component of the PID controller. Further notes at `Td`.
Tn	LREAL	Get, Set	The integrating component of the PID controller. The value is calculated in velocity units per pressure unit and seconds (typically [mm/s / (bar * s)]) The response is calculated if `EnableI=TRUE` and `Tn>=CycleTime`, otherwise it is `0`. The output is limited to `WuLimit`.
WuLimit	LREAL	Get, Set	Effective limitation of the integrating component of the PID controller. Further notes at `Tn`.
EnableM¹	BOOL	Get, Set	Obsolete variant of `.EnableNeg`
EnableP¹	BOOL	Get, Set	Obsolete variant of `.EnablePos`
EnableClipping¹	BOOL	Get, Set	Obsolete variant of `.EnableOutputLimit`

¹Obsolete

Methods

Name	Description
GetBoolParameter	This method is used to read BOOL parameters of the controller. For details see E_PressureControlParam.
GetFloatParameter	This method is used to read LREAL parameters of the controller. For details see E_PressureControlParam.
SetBoolParameter	This method is used to define BOOL parameters of the controller. For details see E_PressureControlParam.
SetFloatParameter	This method is used to define LREAL parameters of the controller. For details see E_PressureControlParam.

Interfaces

Name	Description
I_PressureControlParams_PID	Standard interface to FB_PressureControlParams_PID

Requirements

Development Environment	Target platform	PLC libraries to include
TwinCAT v3.1.4024.66	PC or CX (x64, x86)	Tc3_PlasticFunctions (>= v12.10.0.0)

Further Information