text: <user>
  Create a function block for temperature control in TwinCAT Structured Text<|endoftext|>
  <assistant>
  FUNCTION_BLOCK FB_TemperatureControl
  VAR_INPUT
      fSetpoint       : LREAL;    // Desired temperature setpoint
      fCurrentTemp    : LREAL;    // Current temperature reading
      bEnable         : BOOL;     // Enable control
  END_VAR
  
  VAR_OUTPUT
      fHeaterOutput   : LREAL;    // Heater output (0-100%)
      bAlarm          : BOOL;     // Temperature alarm
      nErrorID        : UDINT;    // Error ID
  END_VAR
  
  VAR
      fbPID           : FB_CTRL_PID;    // PID controller function block
      fKp             : LREAL := 1.0;   // Proportional gain
      fTn             : LREAL := 10.0;  // Integral time
      fTv             : LREAL := 2.0;   // Derivative time
      fTd             : LREAL := 1.0;   // Derivative damping time
      tTaskCycleTime  : TIME := T#10MS; // PLC task cycle time
      fMaxTemp        : LREAL := 100.0; // Maximum allowable temperature
  END_VAR
  
  // Main program
  fbPID(
      fSetpointValue    := fSetpoint,
      fActualValue      := fCurrentTemp,
      bReset            := NOT bEnable,
      fKp               := fKp,
      fTn               := fTn,
      fTv               := fTv,
      fTd               := fTd,
      tTaskCycleTime    := tTaskCycleTime,
      fManSyncValue     := 0,
      bSync             := FALSE,
      eMode             := E_CTRL_MODE.eCTRL_MODE_ACTIVE,
      fOutMaxLimit      := 100,
      fOutMinLimit      := 0
  );
  
  // Set heater output
  fHeaterOutput := LIMIT(0, fbPID.fOut, 100);
  
  // Check for over-temperature condition
  IF fCurrentTemp > fMaxTemp THEN
      bAlarm := TRUE;
      nErrorID := 16#1001; // Over-temperature error
  ELSE
      bAlarm := FALSE;
      nErrorID := 16#0000; // No error
  END_IF
  
  // Brief explanation of the implemented PLC software concept:
  // This function block implements a temperature control system using a PID controller.
  // It takes a setpoint and current temperature as inputs, calculates the appropriate
  // heater output using the PID algorithm, and provides alarm functionality for
  // over-temperature conditions.
  
  // Suggestions for related TwinCAT 3 features or programming techniques:
  // 1. Consider using TwinCAT's Scope View for real-time visualization and tuning of the PID controller.
  // 2. Implement a state machine for more complex temperature control scenarios, such as
  //    warm-up, steady-state, and cool-down phases.
  // 3. Utilize TwinCAT's OPC UA functionality to enable remote monitoring and control of the
  //    temperature control system.<|endoftext|>
  