How do I connect to PI AF Server using AF SDK in C#?

AF SDK is the .NET library for working with PI Asset Framework. Here's how to establish a connection:

Basic Connection

using OSIsoft.AF;
using OSIsoft.AF.Asset;

// Connect to the default PI AF Server
PISystems piSystems = new PISystems();
PISystem piSystem = piSystems.DefaultPISystem;
piSystem.Connect();

// Access an AF Database
AFDatabase db = piSystem.Databases.DefaultDatabase;
Console.WriteLine($"Connected to: {db.Name}");

Connecting to a Specific Server

PISystem piSystem = piSystems["MyAFServer"];
piSystem.Connect();
AFDatabase db = piSystem.Databases["MyDatabase"];

Navigating the AF Hierarchy

// Get root elements
foreach (AFElement element in db.Elements)
{
    Console.WriteLine(element.Name);
    
    // Access attributes
    foreach (AFAttribute attr in element.Attributes)
    {
        AFValue value = attr.GetValue();
        Console.WriteLine($"  {attr.Name} = {value.Value}");
    }
}

Connection Best Practices

• Use using blocks or try/finally to ensure connections are disposed.
• Cache PISystem objects — don't create new connections for every operation.
• Use piSystem.ConnectionInfo to check connection state.
• For web applications, use connection pooling via PISystem.Connect(NetworkCredential).