text: <user>
  Generate TwinCAT 3 Structured Text code for a function block that controls a drug delivery device. The device should have the following features:
  1. Precise control of drug dosage
  2. Safety checks to prevent overdose
  3. Monitoring of drug reservoir levels
  4. Wireless connectivity for remote monitoring
  5. Error handling and logging
  
  Include comments explaining the logic and functionality.<|endoftext|>
  <assistant>
  // FB_DrugDeliveryDevice
  // This function block controls a drug delivery device with precise dosage control,
  // safety features, reservoir monitoring, wireless connectivity, and error handling.
  
  FUNCTION_BLOCK FB_DrugDeliveryDevice
  VAR_INPUT
      fDosage         : LREAL;    // Desired drug dosage in milliliters
      bStartDelivery  : BOOL;     // Trigger to start drug delivery
      bStop           : BOOL;     // Emergency stop
  END_VAR
  
  VAR_OUTPUT
      bDeliveryActive : BOOL;     // Indicates if drug delivery is in progress
      bError          : BOOL;     // Error flag
      nErrorID        : UDINT;    // Error ID for logging and diagnostics
      fReservoirLevel : LREAL;    // Current drug reservoir level in milliliters
  END_VAR
  
  VAR
      fbPump          : FB_Pump;  // Pump control function block
      fbFlowMeter     : FB_FlowMeter;  // Flow meter for precise dosage control
      fbWireless      : FB_WirelessComm;  // Wireless communication function block
      fbErrorLogger   : FB_ErrorLogger;  // Error logging function block
      
      fMaxDosage      : LREAL := 10.0;  // Maximum allowed dosage in milliliters
      fMinReservoirLevel : LREAL := 5.0;  // Minimum reservoir level for operation
  END_VAR
  
  METHOD Deliver
  VAR_INPUT
  END_VAR
      // Safety checks
      IF fDosage > fMaxDosage THEN
          SetError(1, 'Dosage exceeds maximum allowed');
          RETURN;
      END_IF
      
      IF fReservoirLevel < fMinReservoirLevel THEN
          SetError(2, 'Reservoir level too low');
          RETURN;
      END_IF
      
      // Start delivery
      fbPump.Start(fDosage);
      bDeliveryActive := TRUE;
      
      // Monitor flow
      WHILE fbPump.IsRunning() DO
          fbFlowMeter.Update();
          IF fbFlowMeter.GetFlow() > fDosage THEN
              fbPump.Stop();
              SetError(3, 'Flow exceeded dosage');
              RETURN;
          END_IF
      END_WHILE
      
      bDeliveryActive := FALSE;
      
      // Update reservoir level
      fReservoirLevel := fReservoirLevel - fDosage;
      
      // Send data wirelessly
      fbWireless.SendData(fReservoirLevel, fDosage);
  END_METHOD
  
  METHOD SetError
  VAR_INPUT
      nID   : UDINT;
      sText : STRING;
  END_VAR
      bError := TRUE;
      nErrorID := nID;
      fbErrorLogger.LogError(nID, sText);
  END_METHOD
  
  METHOD Reset
  VAR_INPUT
  END_VAR
      bError := FALSE;
      nErrorID := 0;
      bDeliveryActive := FALSE;
      fbPump.Stop();
  END_METHOD
  
  // Main program
  IF bStartDelivery AND NOT bError AND NOT bDeliveryActive THEN
      Deliver();
  END_IF
  
  IF bStop THEN
      Reset();
  END_IF
  
  // Explanation of the implemented PLC software concept:
  // This function block implements a drug delivery device control system.
  // It ensures precise dosage control using a pump and flow meter, implements
  // safety checks to prevent overdosing and reservoir depletion, and includes
  // wireless communication for remote monitoring. Error handling and logging
  // are integrated for improved diagnostics and maintenance.
  
  // Suggestions for enhancement:
  // 1. Implement a PID controller for more precise flow control
  // 2. Add a user interface using TwinCAT HMI for local device control
  // 3. Integrate with TwinCAT IoT for cloud-based monitoring and analytics<|endoftext|>
  