MC_AxCtrlPressureFF_BkPlcMc

The function block regulates the pressure acting on an axis in such a way that the desired default value SetPoint is set up and maintained in Actual. Alternatively, forces can also be used as actual values and setpoints.

In most cases the actual pressure can be logged with function blocks of type MC_AxRtReadPressureSingle_BkPlcMc or MC_AxRtReadPressureDiff_BkPlcMc. Function blocks of type MC_AxRtReadForceSingle_BkPlcMc or MC_AxRtReadForceDiff_BkPlcMc are suitable for an actual force.

Inputs

VAR_INPUT
    Enable:       BOOL:=FALSE; 
    Enable_P:     BOOL:=TRUE; 
    Enable_I:     BOOL:=TRUE; 
    Enable_D:     BOOL:=TRUE;
    Reset:        BOOL:=TRUE; 
    Setpoint:     LREAL:=0.0; 
    Actual:       LREAL:=0.0; 
    FeedVelocity: LREAL:=0.0;
    FeedCharge:   LREAL:=0.0;
    pParam:       POINTER TO ST_TcPctrlParam; 
END_VAR

Name	Type	Description
Enable	BOOL	TRUE at this input activates the controller.
Enable_P	BOOL	A TRUE at this input activates the proportional component of the controller.
Enable_I	BOOL	A TRUE at this input activates the integrator of the controller if the proportional component is active.
Enable_D	BOOL	A TRUE at this input activates the differential component of the controller if the proportional component is active.
Reset	BOOL	TRUE at this input resets the controller. The memory of the I part is cleared.
Setpoint	LREAL	The setpoint of the controller.
Actual	LREAL	The actual value of the controller.
FeedVelocity	LREAL	The default value for a lower-level pre-control.
FeedCharge	LREAL	An instantaneously effective and permanent change in the integral component.
pParam	POINTER TO ST_TcPctrlParam	The address of a structure with the controller parameters. If zero is transferred here, the controller uses the parameters in stAxParams.stPctrl.

Inputs/outputs

VAR_INOUT
    Axis:         Axis_Ref_BkPlcMc;
END_VAR

Name	Type	Description
Axis	Axis_Ref_BkPlcMc	Here, the address of a variable of type Axis_Ref_BkPlcMc (from V3.0) should be transferred.

Outputs

VAR_OUTPUT
    Error:        BOOL;
    ErrorID:      UDINT;
    InWindup:     UDINT; 
    Deviation:    LREAL; 
    Proportional: LREAL; 
    Integrator:   LREAL;
    Differential: LREAL;
    Response:     LREAL;
END_VAR

Name	Type	Description
Error	BOOL	A TRUE here signals an error.
ErrorID	UDINT	A numerically encoded error indication.
InWindup	UDINT	A TRUE here signals that the integrator is limited by the WindupLimit.
Deviation	LREAL	The current controller deviation.
Proportional	LREAL	The current proportional component.
Integrator	LREAL	The current integral component.
Differential	LREAL	The current differential component.
Response	LREAL	The output of the controller.

The controller has a complete PID core, the individual components of which can be switched on and off via Boolean inputs regardless of their parameters.

In addition, a pre-control input is available, which makes it easier to adapt the control against a moving object to the velocity of the object. If necessary, the component of the integrator can be instantaneously changed with the input FeedCharge.