text: <user>
  Create a function block for a simple temperature control system in TwinCAT Structured Text<|endoftext|>
  <assistant>
  FUNCTION_BLOCK FB_TemperatureControl
  VAR_INPUT
      fSetpoint       : REAL;    // Desired temperature setpoint
      fCurrentTemp    : REAL;    // Current temperature reading
      bEnable         : BOOL;    // Enable control
  END_VAR
  
  VAR_OUTPUT
      bHeaterOn       : BOOL;    // Heater control signal
      bCoolerOn       : BOOL;    // Cooler control signal
      bAlarm          : BOOL;    // Alarm signal
  END_VAR
  
  VAR
      fHysteresis     : REAL := 1.0;    // Hysteresis band
      tOnDelay        : TON;            // On delay timer
      tOffDelay       : TOF;            // Off delay timer
  END_VAR
  
  // Main control logic
  IF bEnable THEN
      // Heating control
      IF fCurrentTemp < (fSetpoint - fHysteresis) THEN
          tOnDelay(IN := TRUE, PT := T#5S);
          IF tOnDelay.Q THEN
              bHeaterOn := TRUE;
              bCoolerOn := FALSE;
          END_IF
      ELSIF fCurrentTemp > (fSetpoint + fHysteresis) THEN
          tOffDelay(IN := TRUE, PT := T#5S);
          IF tOffDelay.Q THEN
              bHeaterOn := FALSE;
              bCoolerOn := TRUE;
          END_IF
      END_IF
      
      // Alarm condition
      bAlarm := (fCurrentTemp < (fSetpoint - 10.0)) OR (fCurrentTemp > (fSetpoint + 10.0));
  ELSE
      bHeaterOn := FALSE;
      bCoolerOn := FALSE;
      bAlarm := FALSE;
      tOnDelay(IN := FALSE);
      tOffDelay(IN := FALSE);
  END_IF
  
  (* 
  This function block implements a simple temperature control system with the following features:
  1. Hysteresis control for heating and cooling
  2. Delay timers to prevent rapid cycling
  3. Alarm for significant temperature deviations
  4. Enable/disable functionality
  *)
  
  // Suggested TwinCAT 3 features to enhance this implementation:
  // 1. Use of Structured Text Object-Oriented Programming (ST-OOP) for better code organization
  // 2. Implementation of a PID controller for more precise temperature control
  // 3. Integration with TwinCAT HMI for visualization and user interaction<|endoftext|>
  