Transformation

	Exclusive function for transforming axes This core function is only available for transforming axes.

This core function manages the coupling of the two internal axes of a transforming axis.

To this end, the transformation works internally with three translation paths:

Drive table - Drive position in a load position.

The drive table itself consists of the points in the transferred table.
Is used as the basis for generating the virtual encoder position of the load side.

Load table - load position in a drive position.

Is the inverse function of the transferred load table.
Is used in the full transformation for synchronization of the drive side.
Used in the half transformation to convert the command positions
Is linearized if LowerLimit and/or UpperLimit are within the load positions

Drive table - Reverse translation of an actuator position into a load position.

Is used to check the validity of a target position without linearization.

Syntax:

FUNCTION_BLOCK FB_NcTransformation EXTENDS FB_TrafoCorefunction

Properties

Name	Type	Access	Description
InitState	BOOL	Get, Set	The core function is not completely and successfully initialized.
FB_NcTransformation
IsUpdating	BOOL	Get	TRUE as long as a previously passed table is being processed internally.
LowerLimit	LREAL	Get, Set	Lower limit from which the load table is linearized.
Reversed	LREAL	Get, Set	Reserved for future use.
Table	I_CammingLookUp	Get, Set	Interface for the transformation table to be transferred.
UpperLimit	LREAL	Get, Set	Upper limit from which the load table is linearized.
Valid	BOOL	Get	The transferred table was loaded successfully.
FB_Corefunction
FailedState	BOOL	Get, Set	If IsActivated is TRUE at the same time: Signals the failure of an accepted command. If IsActivated is FALSE at the same time: Signals the rejection of a command.
HasFeedback	BOOL	Get	The core function has responded to a pending command.
IsActivated	BOOL	Get	The core function has an accepted command pending.
IsLocalCmd	BOOL	Get	Signals that the axis is assigned with a command of this core function.
ReadyState	BOOL	Get, Set	The Corefunction is ready for operation, but is not commandable at this time. Possible reasons are: - The axis is not enabled. - Another Corefunction is active. - The Corefunction does not support any commands.

Methods

Name	Description
[`INTERN`] Cyclic()	This method is called cyclically by the axis.
FB_NcTransformation
GetSlot()	Reserves the index of a slot for asynchronous translation function and returns it.
ReleaseSlot(`nSlot`)	Releases a reserved slot.
TranslateFromDrive()	Translates a drive position into a load position using the load table.
TranslateFromLoad()	Reserved for future use.
TranslateToDrive()	Translates a load position into a drive position using the load table.
TranslateToLoad()	Translates a drive position into a load position using the drive table.
UpdateToLinLoad()	Translates a position in a linearized way, depending on the set LowerLimit properties.
[`INTERN`] TranslateToDrivePrio()	Prioritized execution of the `TranslateToDrive()` method.
[`INTERN`] TranslateToLoadPrio()	Prioritized execution of the `TranslateToLoad()` method.

Interfaces

Type	Description
I_Corefunction	Standard interface on FB_Corefunction.
I_Transformation	Standard interface on FB_NcTransformation.
I_CorefunctionFeedback	Standard interface on FB_CorefunctionFeedback.

Example:

// Get specific interface I_AxisTrafoBase from general interface I_AxisBase
IF __QUERYINTERFACE(iAxisBase, iAxisTrafoBase) THEN
    
    CASE nState OF
    0:  // define transformation mechanics (e.g. a crank shaft)
        fbCrankTableGenerator.DriveArm := 50.0;         // [mm]
        fbCrankTableGenerator.LoadArm := 200.0;         // [mm]
        fbCrankTableGenerator.HeightOffset := 0.0;      // [mm]
        fbCrankTableGenerator.DriveLowEnd := 0.0;       // [°]
        fbCrankTableGenerator.DriveHighEnd := 180.0;    // [°]
        
        // configure a table in which the generated characteristic curve is stored
        fbCammingLookup.Equidistance := TRUE;
        fbCammingLookup.Interpolation := E_LookupMode.eSecondOrder;
        fbCammingLookup.SetPoints(181);        // Resultion => 1 point per degree [°]
        fbCrankTableGenerator.LookUp := fbCammingLookup;
        
        // Start table generation
        IF fbCrankTableGenerator.DefineTable() THEN
            nState := nState + 1;
        ELSE
            nState := -1;
        END_IF
        
    1:  // assign the caracteristics curve to the axis
        iAxisTrafoBase.Transformation.Table := fbCrankTableGenerator;
        
        IF iAxisTrafoBase.Transformation.Valid THEN
            nState := nState + 1;
        ELSIF NOT iAxisTrafoBase.Transformation.IsUpdating THEN
            nState := -1;
        END_IF
        
    2:  // transformation is ready to use.

        // Activate full transformation to linearise load side behavior
        iAxisTrafoBase.Synchronise := TRUE;
    
    -1: // error
        
    END_CASE
ELSE
    // interface is not set to an instance deriving FB_AxisTrafoBase (e.g. FB_AxisNcTrafoBase)
    bIncompatible := TRUE;
END_IF

Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT v3.1.4024.55	PC or CX (x64, x86)	Tc3_PlasticFunctions (>= v12.6.1.0)

Further Information