MC_MoveLinRel

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.

- An error is returned if the group is in the GroupDisabled state.
- The maximum number of axes is set by the MaxNumberOfAxes input set in the MC_CreateAxesGrp function block.
- S-Curve motion is not currently supported. The JerkIn physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time input is currently ignored. S-Curve motion and the Jerk argument will be supported in a future release. .

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

See Transition Between Moves for additional information.

Figure 8-185: MC_MoveLinRel

Related Functions

MC_MoveLinAbs, MC_ErrorDescription

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

Arguments

Input

Execute	Description	On the rising edgeA 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 jerkIn 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 three 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_IL"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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