AF SDK Reference

PIDataPipe Class

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PIDataPipe Class

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Last UpdatedJan 12, 2026
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PIDataPipe Class

The PIDataPipe is used to subscribe for data change events on a list of PIPoint instances. The PIPoint instances do not have to be associated with the same PIServer. PIDataPipe instances can sign up for archive, snapshot or timeseries events. The pipe type is specified when the data pipe object is constructed.

Inheritance Hierarchy

SystemObject
OSIsoft.AF.PIPIDataPipe

Namespace: OSIsoft.AF.PI
Assembly: OSIsoft.AFSDK (in OSIsoft.AFSDK.dll) Version: 3.2.0.7

Syntax

public sealed class PIDataPipe : IDisposable

Public NotInheritable Class PIDataPipe
	Implements IDisposable

Dim instance As PIDataPipe

public ref class PIDataPipe sealed : IDisposable

[<SealedAttribute>]
type PIDataPipe =  
    class
        interface IDisposable
    end

The PIDataPipe type exposes the following members.

Constructors

	Name	Description
	PIDataPipe	Constructs a new PIDataPipe used to sign up for events on a list of PIPoint objects

Properties

	Name	Description
	DataPipeStatistics	Contains statistics for the most recent signup or event scan.

Methods

	Name	Description
	AddSignups	Adds a list of PIPoint objects to be monitored by the data pipe. The method returns server level and point level errors in AFErrorsTKey .
	AddSignupsWithInitEvents	Adds a list of PIPoint objects to be monitored by the data pipe and returns the initial events for this list of new signup objects. PIserver level and point level errors can be accessed in the AFListResultsTKey, TResult
	AsReadOnly	Returns a read only list of PIPoint objects currently monitored by the data pipe.
	Close	Terminates the data pipe's connection to the PIServers associated with the monitored PIPoint objects.
	Dispose	Terminates the data pipe's connection to the PIServers associated with the monitored PIPoint objects. This method also releases the resources used by the PIDataPipe. Calling any method after the object has been disposed will result in an exception being thrown.
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetObserverEvents	Trigger retrieval of new events that occurred on the PIPoint objects monitored by the data pipe. The new events will be sent to the IObserver objects registered with the data pipe.
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	GetUpdateEvents	Retrieves new events that occurred on the PIPoint objects monitored by the data pipe.
	ListSignUpsByServer	Return a list of PIPoint objects monitored by the data pipe for the requested PIServer.
	RemoveSignups	Remove a list of PIPoint objects being monitored by the data pipe. The method returns server level and point level errors in AFErrorsTKey .
	Subscribe	Register an IObserver for AFDataPipeEvent with the PIDataPipe. All the AFDataPipeEvents received by the data pipe will be sent to the IObserver.
	ToString	Returns a string that represents the current object. (Inherited from Object.)

Remarks

There are two ways to get the data change events: a) direct GetUpdateEvents method to get events; b) through IObserver of AFDataPipeEvent. The IObserver pattern provides significant performance improvement over direct GetUpdateEvents method for high throughput scenario. Application will have to implement the IObserver and register the IObserver with the data pipe via the Subscribe(IObserverAFDataPipeEvent) method.

Notes to Callers
This method, property, or class is not available in the legacy .NET 3.5 version of the SDK.

Examples

// This example demonstrates how to create a PIDataPipe that receives
// snapshot events for a list of PIPoint objects.

// Get default PI Data Archive
PIServer myServer = PIServers.GetPIServers().DefaultPIServer;

// List to hold the PIPoint objects that we will sign up for updates on
List<string> nameList = new List<string>();
List<string> ptattList = new List<string>();

// Add points we are interested in
nameList.Add("sinusoid");
nameList.Add("sinusoidu");
nameList.Add("cdt158");
nameList.Add("cdm158");
ptattList.Add(PICommonPointAttributes.PointType);
ptattList.Add(PICommonPointAttributes.Zero);
ptattList.Add(PICommonPointAttributes.Span);

IList<PIPoint> myList = PIPoint.FindPIPoints(myServer, nameList, ptattList);

List<AFDataPipeEvent> pipeResults = new List<AFDataPipeEvent>();

// Create a new data pipe for snapshot events
using (PIDataPipe myDataPipe = new PIDataPipe(AFDataPipeType.Snapshot))
{
    // Sign up for updates on the points
    myDataPipe.AddSignups(myList);

    // For the next 30 seconds...
    for (int secondsIndex = 0; secondsIndex < 30; secondsIndex++)
    {
        // Get events that have occurred in the last second
        AFListResults<PIPoint, AFDataPipeEvent> myResults = myDataPipe.GetUpdateEvents(10);

        // If there are some results
        if (myResults.Results.Count > 0)
        {
            // For each event...
            foreach (AFDataPipeEvent mySnapshotEvent in myResults.Results)
            {
                // If the event was added or updated in the snapshot...
                if (mySnapshotEvent.Action == AFDataPipeAction.Add ||
                    mySnapshotEvent.Action == AFDataPipeAction.Update)
                {
                    // Display the new value
                    DisplaySnapshot(mySnapshotEvent.Value.PIPoint.Name, mySnapshotEvent.Value.Value);
                }
                pipeResults.Add(mySnapshotEvent);
            }
        }

        // Wait one second
        System.Threading.Thread.Sleep(1000);
    }
}

private static void DisplaySnapshot(string tagName, object value)
{
    // Display the tag name along with the new snapshot value
    Console.WriteLine("PI Point: {0} Snapshot Value: {1}", tagName, value);
}

AF SDK Reference