MC_ReadActualPosition (motion control read actual position)

The MC_ReadActualPosition instruction returns the actual position of the feedback axis. MC_ReadActualPosition is only applicable to feedback motion.
Operation details:
  • Before executing MC_ReadActualPosition, verify that the axis is in one of the following axis states:
    • Disabled
    • Standstill
    • Discrete Motion
    • Error Stop
  • The actual position for a feedback axis is not reset to 0 after a download. To reset or clear the position for a feedback axis, use the MC_Home instruction or MC_SetPosition instruction.
Languages supported: Function block diagram, ladder diagram, structured text.
This instruction applies to the L50E and L70E controllers that support motion control.
MC_ReadActualPosition
MC_ReadActualPosition
MC_ReadActualPosition parameters
Parameter
Parameter Type
Data Type
Description
AxisIn
Input
FB_AXIS_REF 
For an FB_Axis (feedback axis), use the FB_AXIS_REF data type to define AxisIn.
Enable
Input
BOOL
  • TRUE: Get the value of the parameter continuously while enabled.
  • FALSE: Idle.
Axis
Output
FB_AXIS_REF
Axis output is read-only in ladder diagram programs.
The axis output parameters are defined in the FB_AXIS_REF data type.
Valid
Output
BOOL
  • TRUE: The instruction block is active and new output values are expected.
  • FALSE: The instruction block is inactive.
Busy
Output
BOOL
  • TRUE: The instruction block is not finished.
  • FALSE: The instruction block is finished.
Error
Output
BOOL
Indicates an error occurred.
  • TRUE: An error is detected.
  • FALSE: No error.
ErrorID
Output
UNIT
A unique numeric that identifies the error. The errors for this instruction are defined in Motion control function block error IDs .
Position
Output
REAL
The value of the actual absolute position for feedback motion axis. (in axis' unit [u])

MC_ReadActualPosition examples

MC_ReadActualPosition function block diagram example
MC_ReadActualPosition function block diagram example
MC_ReadActualPosition ladder diagram example
MC_ReadActualPosition ladder diagram example
MC_ReadActualPosition structured text example
MC_ReadActualPosition structured text example
Results
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