MC_MoveContVel

PLCopen motion icon

Function Block A function block groups an algorithm and a set of private data. It has inputs and outputs. - Performs a single-axis non-ending move at a specified velocity with the option of continually updating the ongoing motion with the current input parameters.

Inputs

Input	Data Type	Range	Unit	Default	Description
Execute	BOOL	FALSE, TRUE	N/A	No default	On the rising edge A rising edge is the transition of a digital signal from low to high. It is also called positive edge, request to queue the move.
Axis	AXIS_REF	1, 256	N/A	No default	Name of a declared instance of the AXIS_REF library function. See Modify PLCopen Axis for more information. See AXIS_REF Structure for more information.
Velocity	LREAL	All finite values.	User unit/sec	No default	The target axis velocity. Negative values of velocity move the axis in the negative direction. Positive values move the axis in the positive direction. A value of 0 (zero) is valid. 0 (zero) indicates a deceleration to zero velocity.
Acceleration	LREAL	Positive values.	User unit/sec²	No default	Trapezoidal: Acceleration rate. S-curve: Maximum acceleration. See S-curve and Trapezoidal Acceleration / Deceleration for more information.
Deceleration	LREAL	Positive values.	User unit/sec²	No default	Trapezoidal: Deceleration rate. S-curve: Unused. See S-curve and Trapezoidal Acceleration / Deceleration for more information.
Jerk In physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time	LREAL	No range	User unit/sec³	No default	Trapezoidal: 0 (zero). S-curve: Constant jerk In physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time. See S-curve and Trapezoidal Acceleration / Deceleration for more information.
ContinuousUpdate	BOOL	FALSE, TRUE	N/A	No default	Determines if the inputs of the function block are re-evaluated every cycle or if they are only evaluated on the rising edge of Execute. If TRUE, when the function block is triggered (on the rising edge of Execute), the function block uses the current updated values of the input variables and apply it to the ongoing movement of the axis. This continues as long as ContinuousUpdate stays TRUE. The impact of ContinuousUpdate ends as soon as the function block is no longer busy (Busy output is FALSE) or ContinuousUpdate is set to FALSE.
BufferMode	SINT	See Description	N/A	No default	The specified buffer mode. MC_BUFFER_MODE_ABORTING = 0 = Abort MC_BUFFER_MODE_BUFFERED = 1 = Buffered MC_BUFFER_MODE_BLENDING_PREVIOUS = 2 = Blending Previous MC_BUFFER_MODE_BLENDING_NEXT = 3 = Blending Next MC_BUFFER_MODE_BLENDING_LOW = 4 = Blending Low MC_BUFFER_MODE_BLENDING_HIGH = 5 = Blending High See Buffer Modes for more 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 goes high until 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 for more information.

Remarks

This function or function block returns cached data.
See Program a Multi-Core Controller for more information.

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

After MC_MoveContVel execution begins (Execute input - low to high), follow up changes to input parameters immediately affect the ongoing motion, without requiring an additional low to high transition on the Execute input.
This type of move can be terminated with the MC_Halt function block or by aborting it with another move.

Figure 6-231: MC_MoveContVel

Time Diagram

This example shows the behavior of the combination of a MC_Stop function block with a MC_MoveContVel function block.

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_MoveContVel reports an error indicating the busy MC_Stop command.

Figure 6-232: Time Diagrams: First and Second FBs

Figure 6-233: Time Diagram

FBD Language Example

Not available.

FFLD Language Example

IL Language Example

Not available.

ST Language Example

(* MC_MoveContVel ST "Structured text"
A high-level language that is block structured and syntactically resembles Pascal example *)
Inst_MC_MoveContVel( MovVelReq , Axis1, Vel, 100.0, 100.0, 0, True, MC_BUFFER_MODE_ABORTING );