MC_PositionCorrectionLimiter

The function block MC_PositionCorrectionLimiter writes a correction value (PositionCorrectionValue) at the actual position of an axis. Depending on the correction mode the data are fed either directly or filtered to the axis.

	To use this function block successfully, the "Position Correction" parameter must be activated in the System Manager. The function block should only be executed on enabled axes.

Inputs

VAR_INPUT
    Enable                  :    BOOL;
    PositionCorrectionValue :    LREAL;
    CorrectionMode          :    E_AxisPositionCorrectionMode;
    Acceleration            :    LREAL;
    CorrectionLength        :    LREAL;
END_VAR

Name	Type	Description
Enable	BOOL	Activates continuous writing of the correction value "PositionCorrectionValue". It must be TRUE as long as new correction values are to be accepted.
PositionCorrectionValue	LREAL	Correction value to be added to the actual value of the axis.
CorrectionMode	E_AxisPositionCorrectionMode	Depending on this mode, the correction value "PositionCorrectionValue" is written either directly or filtered.
Acceleration	LREAL	Depending on the "CorrectionMode" the maximum acceleration to reach the new correction value is specified here. In the case of PositionCorrectionMode_Fast this value has a direct effect on the position delta by PLC-tick. Maximum permissible correction value Position delta = acceleration * (PLC cycle time)2. If acceleration is parameterized as 0.0, the position correction is not limited.
CorrectionLength	LREAL	Becomes active when the "CorrectionMode" matches PositionCorrectionMode_FullLength. A change in the "PositonCorrectionValue" is distributed over this correction length.

Inputs/outputs

VAR_IN_OUT
    Axis : AXIS_REF;
END_VAR

Name	Type	Description
Axis	AXIS_REF	Axis data structure that unambiguously addresses an axis in the system. Among other parameters it contains the current axis status, including position, velocity or error state.

Outputs

VAR_OUTPUT
    Busy     :    BOOL;
    Error    :    BOOL;
    ErrorID  :    UDINT;
    Limiting :    BOOL;
END_VAR

Name	Type	Description
Busy	BOOL	TRUE as soon as the function block is active. FALSE when it returns to its original state.
Error	BOOL	TRUE, if an error occurs.
ErrorID	UDINT	If the error output is set, this parameter supplies the error number.
Limiting	BOOL	TRUE if the required correction value "PositionCorrectionValue" is not yet fully accepted.

Requirements

Development environment	Target system type	PLC libraries to include
TwinCAT v3.0.0	PC or CX (x86 or x64)	Tc2_MC2