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Reading and Writing Tags

SQL Database Access

csharp

// Reading tags
double temperature = @Tag.Process.Temperature;
bool motorRunning = @Tag.Motor1.Running;
string batchID = @Tag.Batch.ID;
DateTime timestamp = @Tag.System.CurrentTime;

// Writing tags
@Tag.Setpoint.Value = 75.5;
@Tag.Pump.Start = true;
@Tag.Message.Text = "Process started";

// Array access
double[] values = @Tag.Data.Array;
@Tag.Data.Array[0] = 100;

// Quality and timestamp
TagQuality quality = @Tag.Process.Temperature.Quality;
DateTime lastUpdate = @Tag.Process.Temperature.Timestamp;

Python Tag Access

python

# Reading tags
temperature = @Tag.Process.Temperature
motor_running = @Tag.Motor1.Running
batch_id = @Tag.Batch.ID

# Writing tags
@Tag.Setpoint.Value = 75.5
@Tag.Pump.Start = True
@Tag.Message.Text = "Process started"

# Array operations
import numpy as np
values = np.array(@Tag.Data.Array)
mean_value = np.mean(values)
@Tag.Statistics.Mean = mean_value

# Bulk operations
tags_to_read = ['Tag1', 'Tag2', 'Tag3']
values = @Tag.ReadMultiple(tags_to_read)

Tag Properties and Methods

csharp

 C# Database Operations
public class DatabaseScript
{
    public void ReadFromDatabase()
    {
        // Simple query
        var result = @Dataset.Query("SELECT * FROM Production WHERE Date = TODAY");
        
        // Parameterized query
        var parameters = new Dictionary<string, object>
        {
            { "StartDate", DateTime.Today },
            { "EndDate", DateTime.Now }
        };
        
        var data = @Dataset.ExecuteQuery(
            "SELECT * FROM Production WHERE Timestamp BETWEEN @StartDate AND @EndDate",
            parameters
        );
        
        // Process results
        foreach (var row in data.Rows)
        {
            @Tag.Production.Count = row["Count"];
            @Tag.Production.Quality = row["Quality"];
        }
    }
    
    public void WriteToDatabase()
    {
        // Insert data
        @Dataset.Execute(
            "INSERT INTO BatchRecords (BatchID, StartTime, Product) VALUES (@ID, @Time, @Product)",
            new {
                ID = @Tag.Batch.ID,
                Time = DateTime.Now,
                Product = @Tag.Batch.Product
            }
        );
        
        // Update data
        @Dataset.Execute(
            "UPDATE Equipment SET RunHours = @Hours WHERE ID = @EquipID",
            new {
                Hours = @Tag.Motor.RunHours,
                EquipID = @Tag.Motor.ID
            }
        );
    }
}

Transaction Management

csharp

// Transaction example
public void ExecuteTransaction()
{
    using (var transaction = @Dataset.BeginTransaction())
    {
        try
        {
            // Multiple operations in transaction
            @Dataset.Execute("INSERT INTO Orders ...", transaction);
            @Dataset.Execute("UPDATE Inventory ...", transaction);
            @Dataset.Execute("INSERT INTO Audit ...", transaction);
            
            // Commit if all successful
            transaction.Commit();
        }
        catch (Exception ex)
        {
            // Rollback on error
            transaction.Rollback();
            @Tag.Error.Message = ex.Message;
        }
    }// Tag properties
public class TagProperties
{
    // Basic properties
    string Name { get; }
    object Value { get; set; }
    TagQuality Quality { get; }
    DateTime Timestamp { get; }
    
    // Extended properties
    double Min { get; set; }
    double Max { get; set; }
    string Units { get; }
    string Description { get; }
    
    // Methods
    void ForceValue(object value);
    void Subscribe(Action<TagChangeEvent> handler);
    void Unsubscribe();
    bool WriteWithConfirm(object value, int timeout);
}

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