text: <user>
  Create a function block for a registration system in TwinCAT Structured Text that uses a touch probe for precise position capture<|endoftext|>
  <assistant>
  FUNCTION_BLOCK FB_Registration
  VAR_INPUT
      bExecute         : BOOL;          // Execute registration
      fPosition        : LREAL;         // Position to trigger registration
      tTimeOut         : TIME := T#1S;  // Timeout for registration
  END_VAR
  
  VAR_OUTPUT
      bDone            : BOOL;          // Registration completed
      bBusy            : BOOL;          // Registration in progress
      bError           : BOOL;          // Error occurred
      nErrorID         : UDINT;         // Error ID
      fCapturedPos     : LREAL;         // Captured position
  END_VAR
  
  VAR
      fbTouchProbe     : MC_TouchProbe; // Touch probe function block
      fbTON            : TON;           // Timer for timeout
      AxisRef          : AXIS_REF;      // Axis reference
  END_VAR
  
  // Main program logic
  IF bExecute AND NOT bBusy THEN
      // Initialize registration
      bBusy := TRUE;
      bDone := FALSE;
      bError := FALSE;
      nErrorID := 0;
      fCapturedPos := 0;
      
      // Configure and execute touch probe
      fbTouchProbe(
          Execute := TRUE,
          TouchProbeID := 1,
          TriggerInput := TRIGGER_REF_PROBE_1,
          WindowOnly := TRUE,
          FirstPosition := fPosition - 1,
          LastPosition := fPosition + 1,
          Axis := AxisRef
      );
      
      // Start timeout timer
      fbTON(IN := TRUE, PT := tTimeOut);
  END_IF
  
  // Check for completion or error
  IF bBusy THEN
      IF fbTouchProbe.Done THEN
          bDone := TRUE;
          bBusy := FALSE;
          fCapturedPos := fbTouchProbe.RecordedPosition;
      ELSIF fbTouchProbe.Error THEN
          bError := TRUE;
          bBusy := FALSE;
          nErrorID := fbTouchProbe.ErrorID;
      ELSIF fbTON.Q THEN
          // Timeout occurred
          bError := TRUE;
          bBusy := FALSE;
          nErrorID := 16#8101; // Custom error code for timeout
      END_IF
  END_IF
  
  // Reset execution
  IF NOT bExecute THEN
      bDone := FALSE;
      bBusy := FALSE;
      bError := FALSE;
      nErrorID := 0;
      fbTouchProbe(Execute := FALSE);
      fbTON(IN := FALSE);
  END_IF
  
  (* 
  This function block implements a registration system using a touch probe for precise position capture.
  It utilizes the MC_TouchProbe function block from TwinCAT's motion control library and adds timeout functionality.
  
  Related TwinCAT 3 features and programming techniques:
  1. Motion Control Library: Explore other motion control function blocks for advanced axis control.
  2. State Machine Programming: Implement a more complex state machine for handling various registration scenarios.
  3. Event Logger: Integrate TwinCAT's event logger for detailed error reporting and diagnostics.
  *)<|endoftext|>
  