MC_MoveRelative (motion control move relative)

The MC_MoveRelative instruction commands a controlled motion of a specified distance relative to the actual position at the time of the execution.
Operation details:
  • Because the motion direction for MC_MoveRelative is determined by the current position and the target position, the sign of the Velocity is ignored.
  • MoveRelative completes with Velocity zero if it is not overridden by another function block.
  • If MC_MoveRelative is issued when the
    Micro800
     controller axis state is Standstill and the relative distance to move is zero, the execution of the function block is immediately reported as Done.
  • For a
    Micro800
     controller, the sign of the input Velocity for MC_MoveRelative is ignored because the motion direction is determined by the Current position and the Target position.
Languages supported: Function block diagram, ladder diagram, structured text.
This instruction applies to the L50E and L70E controllers that support motion control.
MC_MoveRelative
MC_MoveRelative

MC_MoveRelative operation

MC_MoveRelative parameters
Parameter
Parameter Types
Data Types
Descriptions
EN
Input
BOOL
Instruction block enable.
  • TRUE: Execute current MC_MoveRelative computation.
  • FALSE: There is no computation.
Applies only to ladder diagram programs.
AxisIn
Input
Use the AXIS_REF data type parameters to define AxisIn.
Execute
Input
BOOL
Indicates when to start motion.
  • TRUE: Start the motion at rising edge.
  • FALSE: Do not start motion.
Distance
Input
REAL
Relative distance for the motion (in technical unit [u]).
Velocity
Input
REAL
Value of the maximum velocity (not necessarily reached) [u/s]. Because the motion direction is determined by input Position, the sign of Velocity is ignored by the function block.
The maximum velocity might not be reached when Jerk = 0.
Acceleration
Input
REAL
Value of the acceleration (increasing energy of the motor) [u/s
2
].
Deceleration
Input
REAL
Value of the deceleration (decreasing energy of the motor) [u/s
2
].
Jerk
Input
REAL
Value of the Jerk [u/s
3
].
BufferMode
Input
SINT
This parameter is not used.
ENO
Output
BOOL
Enable output.
Applies only to ladder diagram programs.
Axis
Output
AXIS_REF
Axis output is read-only in ladder diagram programs.
Done
Output
BOOL
TRUE: Commanded distance reached.
When the in-position input is enabled for an axis, the in-position signal must be set to active before Done = True.
Busy
Output
BOOL
  • TRUE: The instruction block is not finished.
  • FALSE: The instruction block is finished.
Active
Output
BOOL
TRUE: Indicates that the instruction block has control on the axis.
CommandAborted
Output
BOOL
TRUE: Command was overridden by another command, or Error Stop.
Error
Output
BOOL
Indicates that an error occurred.
  • TRUE: An error is detected.
  • FALSE: No error.
ErrorID
Output
UINT
A unique numeric that identifies the error. The errors for this instruction are defined in Motion control function block error IDs.

MC_MoveRelative examples

MC_MoveRelative function block diagram example
MC_MoveRelative function block diagram example
MC_MoveRelative ladder diagram example
MC_MoveRelative ladder diagram example
MC_MoveRelative structured text example
MC_MoveRelative structured text example
MC_MoveRelative result example
Provide Feedback
Have questions or feedback about this documentation? Please submit your feedback here.
Normal