MC_MoveDirRel

Description

MC_MoveDirRel commands a movement of an axes group to a relative position in the specified coordinate system without taking care of how (on which path) the target position is reached.

• 
  

• • An error is returned if the group is in the GroupDisabled state.
  • This function block does not have its own Acceleration, Deceleration, Velocity, and Jerk In physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time arguments. These are set using MC_AxisSetDefaults.
  • 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 Jerk 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.

Figure 7-183: MC_MoveDirRel

Related Functions

MC_MoveDirAbs, MC_ErrorDescription

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

Arguments

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

Input

Execute	Description	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 perform a direct relative move.
	Data type	BOOL
	Range	0, 1
	Unit	N/A
	Default	—
AxesGroup	Description	Reference to an axes group
	Data type	AXES_GROUP_REF
	Range	—
	Unit	N/A
	Default	—
Distance[ ]	Description	An array containing the distance for each axis in the group.
	Data type	LREAL
	Range	[0, Number of axes in group - 1]
	Unit	N/A
	Default	—
CoordSystem	Description	The coordinate system used when commanding the direct relative move. Currently, only the ACS coordinate system is supported. See Coordinate Systems to learn more.
	Data type	SINT
	Range	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. See the table in Buffer Modes
	Data type	SINT MC_BUFFER_MODE_ABORTING = 0 = Abort MC_BUFFER_MODE_BUFFERED = 1 = Buffered
	Range	—
	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 controlling motion.
	Data type	BOOL
CommandAborted	Description	If True, command was aborted by another function block.
	Data type	BOOL
Error	Description	If True, an error has occurred.
	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

Structure Text

Inst_MC_MoveDirRel( ExecuteMove, Group1_Ref, DistanceList, MC_COORDINATE_SYSTEM_ACS, MC_BUFFER_MODE_ABORTING );

IL

            BEGIN_IL "Instruction list"
This is a low-level language and resembles assembly
     CAL Inst_MC_MoveDirRel( ExecuteMove, Group1_Ref, DistanceList, MC_COORDINATE_SYSTEM_ACS, MC_BUFFER_MODE_ABORTING )
END_IL

Function Block Diagram

Ladder Diagram

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