MC_MoveAbsolute_BkPlcMc (from V3.0)

This function block starts and monitors the movement of an axis.

Inputs

VAR_INPUT
    Execute:        BOOL;
    Position:       LREAL;
    Velocity:       LREAL;
    Acceleration:   LREAL;
    Deceleration:   LREAL;
    Jerk:           LREAL;
    Direction:      MC_Direction_BkPlcMc:=MC_Shortest_Way_BkPlcMc;   (ab/from V3.0.8)
    BufferMode:     MC_BufferMode_BkPlcMc:=Aborting_BkPlcMc;        (ab/from V3.0.8)
END_VAR

Name	Type	Description
Execute	BOOL	The movement is initiated by a rising edge at this input.
Position	LREAL	[mm] The target position of the movement in actual value units of the axis.
Velocity	LREAL	[mm/s] The required motion velocity in actual value units of the axis per second.
Acceleration	LREAL	[mm/s²] The required acceleration in actual value units of the axis per square second. If this parameter is 0.0, it is replaced by a default value from the axis parameters.
Deceleration	LREAL	[mm/s²] The required deceleration in actual value units of the axis per square second. If this parameter is 0.0, it is replaced by a default value from the axis parameters.
Jerk	LREAL	[mm/s³] reserved.
Direction	MC_Direction_BkPlcMc	reserved. This input was only amended for compatibility reasons and either should not be assigned, or the constant MC_Shortest_Way_BkPlcMc should be assigned to it. (from V3.0.8)
BufferMode	MC_BufferMode_BkPlcMc	reserved. This input is provided in preparation for a future build. It should currently either not be assigned or assigned the constant Aborting_BkPlcMc. (from V3.0.8)

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 should be transferred.

Outputs

VAR_OUTPUT
    Busy:           BOOL;
    Done:           BOOL;
    CommandAborted: BOOL;
    Error:          BOOL;
    ErrorID:        UDINT;
END_VAR

Name	Type	Description
Busy	BOOL	Indicates that a command is being processed.
Done	BOOL	Successful processing of the movement is indicated here.
CommandAborted	BOOL	Abortion of the movement is indicated here.
Error	BOOL	The occurrence of an error is indicated here.
ErrorID	UDINT	An encoded indication of the cause of the error is provided here.

Behavior of the function block

On a rising edge at Execute the function block checks the transferred axis interface. A number of problems can be detected and reported during this process:

The possibility that Position is located behind an active software limit switch is checked next. In this case the system responds with Error and ErrorID:=dwTcHydErrCdSoftEnd.
Depending on the motion algorithm specified in Axis.pStAxParams^.nProfile the axis may either only be able to begin the movement initiated here when stationary, or may be able to begin from another movement that has not yet been completed. If it is unable at the present time to accept this new order, the system responds with Error and ErrorID:=dwTcHydErrCdNotStartable.
If the axis is already in an error state, or if it is in the process of carrying out a stop operation, it responds with Error and ErrorID:=dwTcHydErrCdNotReady.
If Velocity is too small (less than 1% of the reference velocity) the system responds with Error and ErrorID:=dwTcHydErrCdSetVelo.
If Acceleration is too small (the Velocity cannot be reached within 100 seconds) the system responds with Error and ErrorID:=dwTcHydErrCdAcc.
If Deceleration is too small (the Velocity cannot be reduced within 100 seconds) the system responds with Error and ErrorID:=dwTcHydErrCdAcc.
If the motion algorithm is already indicating an error code, the system responds with Error and ErrorID:= the motion algorithm's error code.

The movement begins if these checks can be carried out without problems. This is done by limiting the parameters Position, Velocity, Acceleration and Deceleration to the maximum permissible values and passing them to the motion algorithm. The axis is now in the McState_DiscreteMotion state, and the function block begins to monitor the movement.

If the motion algorithm reports an error code while the movement is being executed, the system responds with Error and ErrorID:=the motion algorithm's error code. If completion of the movement is prevented by the activity of another function block, the system responds with CommandAborted. If the motion algorithm achieves the target conditions for the axis, the system responds with Done.

A falling edge at Execute clears all the pending output signals. If, while the movement is still active, Execute is set to FALSE, execution of the movement that had started continues unaffected. The signals provided at the end of the movement (Error, ErrorID, CommandAborted, Done) are made available for one cycle.