Function BlockMC_MoveLinRelPLCopen motion iconPipe Network motion icon

Description

MC_MoveLinRel commands interpolated linear movement of an axes group to the specified relative positions. The dimensionality of the move is determined by the number of axes mapped to the group.

When all motion has completed successfully, the state of the axes group goes to GroupStandby.

See Transition Between Moves for additional information.

Figure 7-178: MC_MoveLinRel

Related Functions

MC_MoveLinAbs, MC_ErrorDescription

Coordinated Motion, the top-level topic for Coordinated Motion.

Arguments

Input

Execute

Description

On the rising edgeClosedA rising edge is the transition of a digital signal from low to high. It is also called positive edge request to perform a linear relative move
  Data Type BOOL
  Range 0, 1
  Unit N/A
  Default
AxesGroup

Description

The axis group that will perform the linear relative move
  Data Type AXIS_GROUP_REF
  Range N/A
  Unit N/A
  Default
Distance[]

Description

Array of distances for each axis in the group.
  Data Type LREAL
  Range N/A
  Unit user units
  Default
Velocity

Description

Maximum velocity of the defined path
  Data Type LREAL
  Range

0 < Velocity < ( 20 * Acceleration ) and 0 < Velocity < ( 20 * Deceleration)

See Limitations on Acceleration and Jerk for more information.

  Unit user units per second
  Default
Acceleration

Description

Maximum acceleration
  Data Type LREAL
  Range

0 < Velocity < ( 20 * Acceleration )

See Limitations on Acceleration and Jerk for more information.

  Unit user units per second2
  Default
Deceleration

Description

Maximum deceleration
  Data Type LREAL
  Range

0 < Velocity < ( 20 * Deceleration)

See Limitations on Acceleration and Jerk for more information.

  Unit user units per second2
  Default
Jerk

Description

Maximum jerkClosedIn physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time
  Data Type LREAL
  Range

For trapezoidal velocity profiles: 0

For S-Curve velocity profiles: ( Velocity / 20 ) < Acceleration < ( 2 * Jerk ) and ( Velocity / 20 ) < Deceleration < ( 2 * Jerk )

See Limitations on Acceleration and Jerk for more information.


  • S-Curve motion is currently not supported and the Jerk input is currently ignored. S-Curve motion and the Jerk argument will be supported in a future release.
  Unit user units per second3
  Default
CoordSystem

Description

The coordinate system used when commanding the linear relative move

Currently, only the ACS coordinate system is supported. See Coordinate Systems to learn more.

  Data Type SINT
  Range

One of the following enumeration values:

  • MC_COORDINATE_SYSTEM_ACS = 0
  • MC_COORDINATE_SYSTEM_MCS = 1
  • MC_COORDINATE_SYSTEM_PCS = 2
  Unit N/A
  Default
BufferMode

Description

Defines the chronological sequence of the function block relative to the previous block.

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

The buffer mode is limited to MC_BUFFER_MODE_BUFFERED for groups with more than two axes.

The blending modes (2, 3, 4, & 5) match the path velocity at the active move's endpoint. Some individual axis velocities may make an abrupt change if the path of the next move travels in a different direction. A transition move may be programmed at the TransitionMode input to avoid this.

See the table in Buffer Modes

  Data Type SINT
  Range
  Unit N/A
  Default
TransitionMode

Description

Coupled with the TransitionParameter[ ], this input defines the shape and dynamics of the inserted contour to connect the current motion with the next motion in the queue.

See Transition Between Moves for additional information.

  Data Type SINT
  Range

The value is limited to the following: 

  • MC_TRANSITION_MODE_NONE = 0
  • MC_TRANSITION_MODE_CORNER_DISTANCE = 3

The transition mode is limited to MC_TRANSITION_MODE_NONE for groups with more than two axes.

  Unit N/A
  Default
TransitionParameter[ ]

Description

This array is dependent on the TransitionMode specified. The transition parameter values are applied to the axis group. See Transition Mode Parameters for details.

  Data Type LREAL
  Range

[0, N]

The value of N is dependent on the TransitionMode specified.

  Unit N/A
  Default

Output

Done Description

If True, then the command completed successfully.

  Data type BOOL
Busy Description

If True, then the function block is executing.

  Data type BOOL
Active Description

If True, then the function block is still controlling motion.

  Data type BOOL
CommandAborted Description

If True, then the command was aborted by another function block.

  Data type BOOL
Error Description If True, then an error has occured
  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

      (* Inst_MC_MoveLinRelST example *)
      
Inst_MC_MoveLinRel( ExecuteLinearMove, Group1_Ref, DistanceList, Velocity, Acceleration, Deceleration, Jerk, CoordSystem, BufferMode, TranstionMode, TransitionParams );

IL

BEGIN_ILClosed"Instruction list"
This is a low-level language and resembles assembly
     CAL Inst_MC_MoveLinRel( ExecuteLinearMove, Group1_Ref, DistanceList, Velocity, Acceleration, Deceleration, Jerk, CoordSystem, BufferMode, TransitionMode, TransitionParams )
END_IL

FBD

FFLD

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