Function BlockMC_MoveVelocityPLCopen motion icon

Description

This function block performs a single-axis non-ending move at a specified velocity. This type of move can be terminated with the MC_Halt function block or by aborting it with another move.


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

MC_MoveVelocity

Figure 7-142: MC_MoveVelocity

MC_MoveContVel

Time Diagram

The example below shows the behavior of the combination of a 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.

MC_MoveVelocity: Timing Diagram

Arguments

For more detail on how inputs and outputs work, refer to PLCopen Function Blocks - General Rules

Input

Execute Description Requests to queue the move
  Data type BOOL
  Range False, True
  Unit N/A
  Default
Axis Description Identifier of a declared instance of the AXIS_REF library function. For more details,see "About Axis Name and Number".
  Data type AXIS_REF
  Range [1,256]
  Unit N/A
  Default
Speed Description The target axis speed. Direction is specified by the Direction input parameter.
  Data type LREAL
  Range Positive values
  Unit User unit/sec
  Default
Acceleration Description Trapezoidal: Acceleration rate
S-curve: Maximum acceleration
  Data type LREAL
  Range Positive values
  Unit User unit/sec2
  Default
Deceleration Description Trapezoidal: Deceleration rate
S-curve: Unused
  Data type LREAL
  Range Positive values
  Unit User unit/sec2
  Default
JerkClosedIn physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time Description Trapezoidal: 0
S-curve: Constant jerkClosedIn physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time
  Data type LREAL
  Range
  Unit User unit/sec3
  Default
Direction Description 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.
  Data type SINT
  Range [0, 1]
  Unit N/A
  Default
BufferMode Description The specified buffer mode. For more information see "Buffer Modes".
  Data type SINT
  Range 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
  Unit N/A
  Default

Output

InVelocity Description Indicates the command velocity has reached the programmed velocity
  Data type BOOL
Busy Description High from the moment the Execute input is one-shot to the time the move is ended
  Data type BOOL
Active Description Indicates this move is the active move
  Data type BOOL
CommandAborted Description Indicates the move was aborted
  Data type BOOL
Error Description Indicates an invalid input was specified or the move was terminated due to an error
  Data type BOOL
ErrorID Description Indicates the error if Error output is set to TRUE. See table in PLCopen Function Block ErrorID Output
  Data type INT

Example

Structured Text

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

Ladder Diagram

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