text: <user>
  Create a function block for motion control in TwinCAT Structured Text that implements a start/stop logic for two motors with interlocking, ensuring only one motor can run at a time.<|endoftext|>
  <assistant>
  FUNCTION_BLOCK FB_MotorControl
  VAR_INPUT
      bStartMotor1 : BOOL;
      bStopMotor1  : BOOL;
      bStartMotor2 : BOOL;
      bStopMotor2  : BOOL;
  END_VAR
  VAR_OUTPUT
      bMotor1Running : BOOL;
      bMotor2Running : BOOL;
      bError         : BOOL;
      nErrorID       : UDINT;
  END_VAR
  VAR
      fbMotor1 : FB_Motor;
      fbMotor2 : FB_Motor;
  END_VAR
  
  // Main program logic
  IF bStartMotor1 AND NOT bMotor2Running THEN
      fbMotor1.Start();
  ELSIF bStopMotor1 THEN
      fbMotor1.Stop();
  END_IF
  
  IF bStartMotor2 AND NOT bMotor1Running THEN
      fbMotor2.Start();
  ELSIF bStopMotor2 THEN
      fbMotor2.Stop();
  END_IF
  
  // Update output variables
  bMotor1Running := fbMotor1.IsRunning;
  bMotor2Running := fbMotor2.IsRunning;
  
  // Error handling
  bError := fbMotor1.HasError OR fbMotor2.HasError;
  IF bError THEN
      IF fbMotor1.HasError THEN
          nErrorID := fbMotor1.ErrorID;
      ELSE
          nErrorID := fbMotor2.ErrorID;
      END_IF
  END_IF
  
  (* 
  This function block implements a start/stop logic for two motors with interlocking.
  It ensures that only one motor can run at a time by checking the status of the other motor
  before starting. Error handling is also implemented to capture and report any issues.
  *)
  
  // Suggested TwinCAT 3 features or programming techniques:
  // 1. Use of FB_Motor function block for encapsulating motor control logic
  // 2. Implementation of a state machine for more complex motor control scenarios
  // 3. Integration with TwinCAT's motion control libraries for advanced functionality<|endoftext|>
  