text: <user>
  Create a function block for motion control in TwinCAT Structured Text that implements a simple point-to-point movement with velocity control and error handling.<|endoftext|>
  <assistant>
  Here's a TwinCAT 3 Structured Text function block for point-to-point motion control with velocity control and error handling:
  
  ```ST
  FUNCTION_BLOCK FB_PointToPointMotion
  VAR_INPUT
      bExecute        : BOOL;     // Command to start the motion
      fTargetPosition : LREAL;    // Target position in user units
      fVelocity       : LREAL;    // Maximum velocity in user units/second
  END_VAR
  
  VAR_OUTPUT
      bDone           : BOOL;     // Motion complete
      bBusy           : BOOL;     // Motion in progress
      bError          : BOOL;     // Error occurred
      nErrorID        : UDINT;    // Error ID
  END_VAR
  
  VAR
      fbMoveAbsolute  : MC_MoveAbsolute;
      fbReset         : MC_Reset;
      AxisRef         : AXIS_REF;
      eState          : (IDLE, MOVING, ERROR, RESET);
  END_VAR
  
  // Main program logic
  CASE eState OF
      IDLE:
          IF bExecute THEN
              fbMoveAbsolute(
                  Axis := AxisRef,
                  Execute := TRUE,
                  Position := fTargetPosition,
                  Velocity := fVelocity
              );
              eState := MOVING;
              bBusy := TRUE;
          END_IF
  
      MOVING:
          fbMoveAbsolute(Axis := AxisRef);
          IF fbMoveAbsolute.Done THEN
              fbMoveAbsolute(Axis := AxisRef, Execute := FALSE);
              bDone := TRUE;
              bBusy := FALSE;
              eState := IDLE;
          ELSIF fbMoveAbsolute.Error THEN
              bError := TRUE;
              nErrorID := fbMoveAbsolute.ErrorID;
              eState := ERROR;
          END_IF
  
      ERROR:
          fbReset(Axis := AxisRef, Execute := TRUE);
          IF fbReset.Done THEN
              fbReset(Axis := AxisRef, Execute := FALSE);
              bError := FALSE;
              nErrorID := 0;
              eState := IDLE;
          END_IF
  
      RESET:
          fbReset(Axis := AxisRef);
          IF fbReset.Done THEN
              fbReset(Axis := AxisRef, Execute := FALSE);
              eState := IDLE;
          END_IF
  END_CASE
  ```
  
  This function block implements a simple point-to-point motion control with the following features:
  1. Uses MC_MoveAbsolute for positioning
  2. Implements a state machine for motion control flow
  3. Includes error handling and automatic reset
  4. Provides status outputs (Done, Busy, Error)
  
  To enhance this implementation, consider the following TwinCAT 3 features:
  1. TwinCAT NC - for more advanced motion control capabilities
  2. TwinCAT PLC Library: Tc2_MC2 - for additional motion control function blocks
  3. TwinCAT Scope View - for visualizing and analyzing motion profiles<|endoftext|>
  