Automated Assembly Line for Pharmaceutical

PROGRAM ASSEMBLY_LINE_STATION_CONTROL
VAR
    // Station Sensors
    station1_part_present : BOOL;
    station2_part_present : BOOL;
    station3_part_present : BOOL;
    operation_complete : ARRAY[1..3] OF BOOL;

    // Outputs
    conveyor_move : BOOL;
    station_clamp : ARRAY[1..3] OF BOOL;
    station_tool : ARRAY[1..3] OF BOOL;

    // State Machine
    state : INT := 0;  // 0=Wait, 1=Process, 2=Transfer
    timer : INT := 0;

    // Operation Times (100ms cycles)
    OPERATION_TIME : ARRAY[1..3] OF INT := [50, 80, 60];
    TRANSFER_TIME : INT := 20;

    // Part Tracking
    parts_completed : INT := 0;
    cycle_time : INT := 0;


    // FDA 21 CFR Part 11 & EU GMP Compliance
    Batch_Number : STRING[20];
    Batch_Start_Time : DATE_AND_TIME;
    Batch_Status : INT;  // 0=Pending, 1=Active, 2=Complete, 3=Quarantine

    // Electronic Batch Records (EBR)
    Recipe_ID : STRING[20];
    Material_Lot_Numbers : ARRAY[1..10] OF STRING[20];
    Critical_Process_Parameters_OK : BOOL;

    // Environmental Monitoring (Cleanroom)
    Room_Classification : STRING[10];  // ISO 5, ISO 7, ISO 8
    Particle_Count : REAL;
    Room_Pressure_Differential : REAL;  // Positive pressure in Pa
    Pressure_Alarm : BOOL;

    // Validation & Qualification
    Equipment_Qualified : BOOL;
    IQ_OQ_PQ_Status : INT;  // 1=IQ, 2=OQ, 3=PQ Complete
    Calibration_Due_Date : DATE;
    Calibration_Valid : BOOL;

    // Audit Trail Variables
    User_ID : STRING[20];
    Operation_Timestamp : DATE_AND_TIME;
    Change_Logged : BOOL;
    Electronic_Signature_Required : BOOL;

    // Sterility Assurance
    Sterilization_Cycle_Complete : BOOL;
    Sterility_Validated : BOOL;
    Bioburden_Acceptable : BOOL;
END_VAR

// ==========================================
// BASE APPLICATION LOGIC
// ==========================================

timer := timer + 1;
cycle_time := cycle_time + 1;

CASE state OF
    0: // Wait for all stations ready
        conveyor_move := FALSE;

        // Check if all stations have parts and completed previous operation
        IF station1_part_present AND station2_part_present AND
           station3_part_present THEN
            state := 1;
            timer := 0;
            // Clamp all parts
            station_clamp[1] := TRUE;
            station_clamp[2] := TRUE;
            station_clamp[3] := TRUE;
        END_IF;

    1: // Process all stations simultaneously
        // Activate tools based on timer
        FOR i := 1 TO 3 DO
            IF timer < OPERATION_TIME[i] THEN
                station_tool[i] := TRUE;
            ELSE
                station_tool[i] := FALSE;
                operation_complete[i] := TRUE;
            END_IF;
        END_FOR;

        // When all operations complete
        IF operation_complete[1] AND operation_complete[2] AND
           operation_complete[3] THEN
            state := 2;
            timer := 0;
            // Release clamps
            station_clamp[1] := FALSE;
            station_clamp[2] := FALSE;
            station_clamp[3] := FALSE;
        END_IF;

    2: // Transfer parts to next station
        conveyor_move := TRUE;

        IF timer > TRANSFER_TIME THEN
            state := 0;
            timer := 0;
            parts_completed := parts_completed + 1;
            cycle_time := 0;  // Reset for next cycle

            // Reset operation flags
            operation_complete[1] := FALSE;
            operation_complete[2] := FALSE;
            operation_complete[3] := FALSE;
        END_IF;
END_CASE;

// ==========================================
// PHARMACEUTICAL SPECIFIC LOGIC
// ==========================================

    // GMP Batch Control - No production without batch record
    IF Batch_Status <> 1 THEN  // Not Active
        Production_Enable := FALSE;
    END_IF;

    // Critical Process Parameters (CPP) Validation
    Critical_Process_Parameters_OK :=
        (Temperature >= Recipe_Temp_Min AND Temperature <= Recipe_Temp_Max) AND
        (Pressure >= Recipe_Pressure_Min AND Pressure <= Recipe_Pressure_Max) AND
        (Mix_Speed >= Recipe_Speed_Min AND Mix_Speed <= Recipe_Speed_Max);

    IF NOT Critical_Process_Parameters_OK THEN
        Batch_Status := 3;  // Quarantine batch
        Production_Enable := FALSE;
        // Log deviation for quality review
    END_IF;

    // Cleanroom Environmental Monitoring
    IF Room_Pressure_Differential < Min_Pressure_Diff THEN
        Pressure_Alarm := TRUE;
        Production_Enable := FALSE;
        // Environmental excursion requires investigation
    END_IF;

    IF Particle_Count > Max_Particle_Limit THEN
        Room_Classification := 'FAIL';
        Production_Enable := FALSE;
        // Cleanroom integrity compromised
    END_IF;

    // Equipment Qualification Check
    Calibration_Valid := (Current_Date <= Calibration_Due_Date);

    IF NOT Equipment_Qualified OR NOT Calibration_Valid THEN
        Production_Enable := FALSE;
        // Equipment must be qualified and calibrated
    END_IF;

    // Audit Trail - Log all critical changes
    IF Parameter_Changed THEN
        Operation_Timestamp := CURRENT_DATETIME();
        Change_Logged := TRUE;
        Electronic_Signature_Required := TRUE;
        // Store: User_ID, Old_Value, New_Value, Reason, Timestamp
    END_IF;

    // Material Traceability
    FOR i := 1 TO 10 DO
        IF Material_Lot_Numbers[i] = '' THEN
            Material_Traceability_Complete := FALSE;
            // All materials must have lot tracking
        END_IF;
    END_FOR;

// ==========================================
// PHARMACEUTICAL SAFETY INTERLOCKS
// ==========================================

    // GMP Production Interlocks
    Production_Allowed := Equipment_Qualified
                          AND Calibration_Valid
                          AND (Batch_Status = 1)
                          AND Critical_Process_Parameters_OK
                          AND NOT Pressure_Alarm
                          AND (Particle_Count <= Max_Particle_Limit)
                          AND Sterility_Validated
                          AND Material_Traceability_Complete;

    // Batch Integrity Protection
    IF Emergency_Stop OR Critical_Alarm THEN
        Batch_Status := 3;  // Automatic quarantine
        // Batch requires quality investigation
    END_IF;

    // Cross-Contamination Prevention
    IF Previous_Product <> Current_Product THEN
        IF NOT Changeover_Cleaning_Complete THEN
            Production_Enable := FALSE;
            // Prevent cross-contamination
        END_IF;
    END_IF;