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
      fHeaterOutput   : REAL;    // Heater output (0-100%)
      bAlarm          : BOOL;    // High temperature alarm
  END_VAR
  
  VAR
      fError          : REAL;    // Temperature error
      fKp             : REAL := 2.0;    // Proportional gain
      fMaxTemp        : REAL := 100.0;  // Maximum safe temperature
  END_VAR
  
  // Main temperature control logic
  METHOD Control
  VAR_INPUT
  END_VAR
  // =========================================================
  
  IF bEnable THEN
      // Calculate error
      fError := fSetpoint - fCurrentTemp;
      
      // Simple proportional control
      fHeaterOutput := fKp * fError;
      
      // Limit output to 0-100%
      fHeaterOutput := LIMIT(0.0, fHeaterOutput, 100.0);
      
      // Check for high temperature alarm
      IF fCurrentTemp > fMaxTemp THEN
          bAlarm := TRUE;
          fHeaterOutput := 0.0;  // Safety shutdown
      ELSE
          bAlarm := FALSE;
      END_IF
  ELSE
      // System disabled
      fHeaterOutput := 0.0;
      bAlarm := FALSE;
  END_IF
  
  // =========================================================
  END_METHOD
  
  This function block implements a simple temperature control system using TwinCAT 3 Structured Text. It uses proportional control to adjust a heater output based on the difference between the setpoint and current temperature. The code includes input validation, output limiting, and a high temperature alarm for safety.
  
  Related TwinCAT 3 features that could enhance this implementation:
  1. PLC Library: Tc2_TemperatureController - This library provides advanced PID control functions for more precise temperature regulation.
  2. Scope View - TwinCAT 3's built-in oscilloscope for real-time visualization and tuning of the control loop.
  3. TwinCAT HMI - Create a user interface for monitoring and adjusting the temperature control system.<|endoftext|>
  