MC_MoveVelocity

PLCopen motion icon

Function Block - Performs a single-axis, non-ending move at a specified velocity.

Inputs

Input	Data Type	Range	Unit	Default	Description
Execute	BOOL	FALSE, TRUE	N/A	No default	On the rising edge, request to queue the move.
Axis	AXIS_REF	1 to 256	N/A	No default	Name of a declared instance of the AXIS_REF library function. See Axis Name and Number. See AXIS_REF Structure.
Speed	LREAL	Positive values.	User unit/sec	No default	The target axis speed. Direction is specified by the Direction input parameter.
Acceleration	LREAL	Positive values.	User unit/sec²	No default	Trapezoidal: Acceleration rate. S-curve: Maximum acceleration. See S-curve and Trapezoidal Acceleration / Deceleration.
Deceleration	LREAL	Positive values.	User unit/sec²	No default	Trapezoidal: Deceleration rate. S-curve: Unused. See S-curve and Trapezoidal Acceleration / Deceleration.
Jerk	LREAL	No range	User unit/sec³	No default	Trapezoidal: 0 (zero). S-curve: Constant jerk. See S-curve and Trapezoidal Acceleration / Deceleration.
Direction	SINT	0, 1	N/A	No default	A 0 or False value specifies that the axis should move in the positive direction. A 1 or True value specifies that the axis should move in the negative direction.
BufferMode	SINT	MC_BUFFER_MODE_ABORTING MC_BUFFER_MODE_BUFFERED MC_BUFFER_MODE_BLENDING_PREVIOUS MC_BUFFER_MODE_BLENDING_NEXT MC_BUFFER_MODE_BLENDING_LOW MC_BUFFER_MODE_BLENDING_HIGH	N/A	No default	The specified buffer mode. See Buffer Modes for detailed information.

Outputs

Output	Data Type	Range	Unit	Description
InVelocity	BOOL	No range	N/A	Indicates the command velocity has reached the programmed velocity.
Busy	BOOL	No range	N/A	High from the moment the Execute input is one-shot to the time the move is ended.
Active	BOOL	No range	N/A	Indicates this move is the Active move.
CommandAborted	BOOL	No range	N/A	Indicates the move was aborted.
Error	BOOL	No range	N/A	Indicates either: An invalid input was specified. The move was terminated due to an error.
ErrorID	INT	No range	N/A	Indicates the error if Error output is TRUE. See PLCopen Function Block ErrorIDs.

Remarks

This function block starts a motion-related action and stores data for calculations and error checking.
If using a dual-core controller, see Call Function Blocks Multiple Times in the Same Cycle.

Consider using the MC_MoveContVel function block.
It is more flexible and allows for the continuous update of motion parameters.

This type of move can be terminated with the MC_Halt function block or by aborting it with another move.
See Function Blocks - General Rules about how inputs and outputs work.

Figure 1: MC_MoveVelocity

Time Diagram

These images show two examples of the combination behavior of an MC_Stop FB with a MC_MoveVelocity FB.

A rotating axis is ramped down with FB2 MC_Stop.
The axis rejects motion commands as long as MC_Stop parameter “Execute” = TRUE.
FB1 MC_MoveVelocity reports an error indicating the busy MC_Stop command.

Figure 2: Time Diagrams: First and Second FBs

Figure 3: Time Diagram

FBD Language Example

Not available.

FFLD Language Example

IL Language Example

Not available.

ST Language Example

            (* MC_MoveVelocity ST example *)
            
Inst_MC_MoveVelocity( MovVelReq , Axis1, 200.0, 100.0, 100.0, 0, True, MC_BUFFER_MODE_ABORTING );